What pipes are provided for pipelines of heating networks. Legislative base of the Russian Federation. Building regulations

Active Edition from 24.06.2003

Document name	"HEAT NETWORKS. BUILDING NORMS AND RULES. SNiP 41-02-2003" (approved by the Decree of the Gosstroy of the Russian Federation of 06.24.2003 N 110)
Document type	decree, norms, list, rules
Host body	gosstroy rf
Document Number	110
Acceptance date	01.01.1970
Revision date	24.06.2003
Date of registration in the Ministry of Justice	01.01.1970
Status	valid
Publication	At the time of inclusion in the database, the document was not published
Navigator	Notes

"HEAT NETWORKS. BUILDING NORMS AND RULES. SNiP 41-02-2003" (approved by the Decree of the Gosstroy of the Russian Federation of 06.24.2003 N 110)

Introduction

Requirements for safety, reliability, and survivability of heat supply systems have been established.

When developing the SNiP, normative materials from leading Russian and foreign companies were used, and 17 years of experience in applying the current standards by design and operating organizations in Russia were taken into account.

In building codes and regulations for the first time:

Norms of environmental and operational safety, readiness (quality) of heat supply have been introduced; extended application of the criterion of the probability of no-failure operation;

the principles and requirements for ensuring survivability in off-design (extreme) conditions are formulated, the signs of district heating systems are clarified;

standards for the application of reliability criteria in the design of heat networks have been introduced;

Criteria for the selection of heat-insulating structures, taking into account fire safety, are given.

The following took part in the development of SNiP: Ph.D. tech. Sciences Ya.A. Kovylyansky, A.I. Korotkov, Ph.D. tech. Sciences G.Kh. Umerkin, A.A. Sheremetova, L.I. Zhukovskaya, L.V. Makarova, V. I. Zhurina, Ph.D. tech. Sciences B.M. Krasovsky, Ph.D. tech. Sciences A.V. Grishkova, Ph.D. tech. Sciences T.N. Romanova, Ph.D. tech. Sciences B.M. Shoikhet, L. V. Stavritskaya, Dr. Sci. Sciences A.P. Akolzin, Ph.D. tech. Sciences I.L. Meisel, E.M. Shmyrev, L.P. Kanina, L.D. Satanov, R.M. Sokolov, Dr. tech. Sciences Yu.V. Balaban-Irmenin, A.I. Kravtsov, Sh.N. Abaiburov, V.N. Simonov, Ph.D. tech. Sciences V.I. Livchak, A.V. Fisher, Yu.U. Yunusov, N.G. Shevchenko, Ph.D. tech. Sciences V.Ya. Magalif, A.A. Khandrikov, L.E. Lyubetsky, Ph.D. tech. Sciences R.L. Ermakov, B.C. Votintsev, T.F. Mironova, Dr. tech. Sciences A.F. Shapoval, V.A. Glukharev, V.P. Bovbel, L.S. Vasiliev.

1 AREA OF USE

The composition of heat networks includes buildings and structures of heat networks: pumping stations, heat points, pavilions, chambers, drainage devices, etc.

These standards consider district heating systems (hereinafter referred to as DH) in terms of their interaction in a single technological process of production, distribution, transportation and consumption of heat.

These norms and rules should be observed when designing new and reconstructing, modernizing and technically re-equipping existing heat networks (including facilities on heat networks).

2 NORMATIVE REFERENCES 3 TERMS AND DEFINITIONS

The following terms and definitions are used in these standards.

District heating system - a system consisting of one or more heat sources, heat networks (regardless of the diameter, number and length of external heat pipelines) and heat consumers.

The probability of failure-free operation of the system [R] is the ability of the system to prevent failures that lead to a temperature drop in heated rooms of residential and public buildings below +12 °C, in industrial buildings below +8 °C, more than the number of times established by the standards.

Availability (quality) coefficient of the system [Kg] - the probability of a working state of the system at an arbitrary point in time to maintain the calculated internal temperature in the heated premises, except for periods of temperature decrease allowed by the standards.

System survivability [L] - the ability of the system to maintain its performance in emergency (extreme) conditions, as well as after long (more than 54 hours) shutdowns.

Service life of heat networks - a period of time in calendar years from the date of commissioning, after which an expert examination of the technical condition of the pipeline should be carried out in order to determine the admissibility, parameters and conditions for further operation of the pipeline or the need for its dismantling.

4 CLASSIFICATION

4.2 Consumers of heat according to the reliability of heat supply are divided into three categories:

For example, hospitals, maternity hospitals, day care centers for children, art galleries, chemical and special industries, mines, etc.

residential and public buildings up to 12 °С;

industrial buildings up to 8 °C.

5 General provisions

A) for the existing development of settlements and existing industrial enterprises - for projects with clarification on actual heat loads;

b) for industrial enterprises planned for construction - according to the consolidated norms for the development of the main (core) production or projects of similar production;

c) for residential areas planned for development - according to aggregated indicators of the density of placement of thermal loads or according to the specific thermal characteristics of buildings and structures in accordance with the master plans for the development of areas of the settlement.

5.2 Estimated heat loads in the design of heat networks are determined according to the data of specific new construction projects, and the existing one - according to actual heat loads. In the absence of data, it is allowed to follow the instructions in 5.1. Average loads on hot water supply of individual buildings are allowed to be determined according to SNiP 2.04.01.

5.3 Estimated heat losses in heat networks should be determined as the sum of heat losses through the insulated surfaces of pipelines and the average annual losses of the heat carrier.

5.4 In case of accidents (failures) at the heat source, its output manifolds during the entire repair and recovery period must be provided with:

supply of 100% of the required heat to consumers of the first category (unless other modes are provided for by the contract);

supply of heat for heating and ventilation to housing and communal and industrial consumers of the second and third categories in the amounts indicated in table 1;

emergency mode of steam and process hot water consumption set by the consumer;

The emergency thermal mode of operation of non-switchable ventilation systems specified by the consumer;

Table 1

Note - The table corresponds to the outdoor temperature of the coldest five-day period with a security of 0.92.

Average daily heat consumption for the heating period for hot water supply (if it is impossible to turn it off).

5.5 When several heat sources work together for a single district (city) heat network, mutual redundancy of heat sources should be provided, providing an emergency mode according to 5.4.

6 HEAT SUPPLY AND HEAT NETWORKS

6.11 Water heating networks should be designed, as a rule, with two pipes, simultaneously supplying heat for heating, ventilation, hot water supply and technological needs.

Multi-pipe and single-pipe heating networks are allowed to be used during a feasibility study.

Heat networks transporting network water in one direction in open heat supply systems, with above-ground laying, it is allowed to design in a single-pipe design with a transit length of up to 5 km. With a greater length and the absence of reserve feeding of the DH from other sources of heat, heat networks should be carried out in two (or more) parallel heat pipelines.

Independent heat networks for connecting technological heat consumers should be provided if the quality and parameters of the heat carrier differ from those accepted in heat networks.

6.12 The scheme and configuration of heat networks should ensure heat supply at the level of specified reliability indicators by:

application of the most advanced designs and technical solutions;

joint work of heat sources;

laying of reserve heat pipelines;

devices of jumpers between thermal networks of adjacent thermal regions.

6.13 Heating networks can be ring and dead-end, redundant and non-redundant.

The number and location of backup pipeline connections between adjacent heat pipelines should be determined by the criterion of the probability of failure-free operation.

6.14 Consumer heating and ventilation systems must be connected to two-pipe water heating networks directly according to a dependent connection scheme.

According to an independent scheme, which provides for the installation of water heaters in heat points, it is allowed to connect other consumers when justifying the heating and ventilation system of buildings 12 floors and above, if independent connection is due to the hydraulic mode of the system.

6.15 The quality of source water for open and closed heat supply systems must meet the requirements of SanPiN 2.1.4.1074 and the rules for the technical operation of power plants and networks of the Ministry of Energy of Russia.

For closed heat supply systems in the presence of thermal deaeration, it is allowed to use industrial water.

6.16 Estimated hourly water consumption to determine the productivity of water treatment and the corresponding equipment for feeding the heat supply system should be taken:

in closed heat supply systems - 0.75% of the actual volume of water in the pipelines of heat networks and the heating and ventilation systems of buildings connected to them. At the same time, for sections of heating networks with a length of more than 5 km from heat sources without heat distribution, the estimated water flow should be taken equal to 0.5% of the volume of water in these pipelines;

in open heat supply systems - equal to the calculated average water consumption for hot water supply with a coefficient of 1.2 plus 0.75% of the actual volume of water in the pipelines of heat networks and the heating, ventilation and hot water supply systems of buildings connected to them. At the same time, for sections of heating networks with a length of more than 5 km from heat sources without heat distribution, the estimated water flow should be taken equal to 0.5% of the volume of water in these pipelines;

For individual heating networks of hot water supply in the presence of storage tanks - equal to the calculated average water consumption for hot water supply with a coefficient of 1.2; in the absence of tanks - according to the maximum water consumption for hot water supply plus (in both cases) 0.75% of the actual volume of water in the pipelines of the networks and the hot water supply systems of buildings connected to them.

6.17 For open and closed heat supply systems, an additional emergency make-up of chemically untreated and non-deaerated water should be provided, the flow rate of which is taken in the amount of 2% of the volume of water in the pipelines of heat networks and the heating and ventilation systems connected to them and in hot water supply systems for open heat supply systems. If there are several separate heat networks extending from the heat source collector, emergency make-up may be determined only for one heat network with the largest volume. For open heat supply systems, emergency make-up should be provided only from domestic and drinking water supply systems.

6.18 The volume of water in heat supply systems, in the absence of data on actual volumes of water, is allowed to be taken equal to 65 m3 per 1 MW of the calculated heat load with a closed heat supply system, 70 m3 per 1 MW - with an open system and 30 m3 per 1 MW of average load - with separate networks of hot water supply.

6.19 Placement of hot water storage tanks is possible both at the heat source and in areas of heat consumption. At the same time, storage tanks with a capacity of at least 25% of the total estimated capacity of the tanks should be provided at the heat source. The inner surface of the tanks must be protected from corrosion, and the water in them must be protected from aeration, while continuous renewal of the water in the tanks must be provided.

6.20 For open heat supply systems, as well as for separate heat networks for hot water supply, storage tanks of chemically treated and deaerated make-up water, with a design capacity equal to ten times the average hourly water consumption for hot water supply, should be provided.

6.21 In closed heat supply systems on heat sources with a capacity of 100 MW or more, tanks for the supply of chemically treated and deaerated make-up water with a capacity of 3% of the volume of water in the heat supply system should be provided, while water renewal in the tanks should be ensured.

The number of tanks, regardless of the heat supply system, is taken at least two by 50% of the working volume.

6.22 In DH with heat pipelines of any length from the heat source to heat consumption areas, it is allowed to use heat pipelines as storage tanks.

6.23 When a group of storage tanks is located outside the territory of heat sources, it must be fenced with a common shaft with a height of at least 0.5 m.

6.24 It is not allowed to install hot water storage tanks in residential areas. The distance from the hot water storage tanks to the border of residential areas must be at least 30 m. At the same time, on soils of the 1st type of subsidence, the distance, in addition, must be at least 1.5 thickness of the subsiding soil layer.

When placing storage tanks outside the territory of heat sources, their fencing should be provided at least 2.5 m high to prevent unauthorized persons from accessing the tanks.

6.25 Hot water storage tanks for consumers should be provided in the hot water supply systems of industrial enterprises to equalize the shift schedule of water consumption by facilities that have concentrated short-term water consumption for hot water supply.

For objects of industrial enterprises that have a ratio of the average heat load for hot water supply to the maximum heat load for heating is less than 0.2, storage tanks are not installed.

6.26 To reduce the loss of network water and, accordingly, heat during planned or forced emptying of heat pipes, it is allowed to install special storage tanks in heat networks, the capacity of which is determined by the volume of heat pipes between two sectional valves.

7 HEAT MEDIA AND THEIR PARAMETERS

7.1 In district heating systems for heating, ventilation and hot water supply of residential, public and industrial buildings, as a rule, water should be taken as a heat carrier.

The possibility of using water as a heat carrier for technological processes should also be checked.

The use of steam for enterprises as a single coolant for technological processes, heating, ventilation and hot water supply is allowed with a feasibility study.

7.2 The maximum design temperature of network water at the outlet of the heat source, in heat networks and heat receivers is established on the basis of technical and economic calculations.

If there is a load of hot water supply in closed heat supply systems, the minimum temperature of the network water at the outlet of the heat source and in the heat networks should ensure the possibility of heating the water supplied to the hot water supply to the normalized level.

7.3 The temperature of the network water returned to thermal power plants with combined heat and power generation is determined by a feasibility study. The temperature of the network water returned to the boiler rooms is not regulated.

7.4 When calculating the schedules of heating water temperatures in district heating systems, the beginning and end of the heating period at the average daily outdoor temperature are taken:

8 °С in areas with an estimated outdoor air temperature for heating design up to minus 30 °С and an average calculated internal air temperature of heated buildings of 18 °С;

10 °C in areas with an estimated outdoor air temperature for heating design below minus 30 °C and an average design temperature of the indoor air of heated buildings of 20 °C.

The average design temperature of the internal air of heated industrial buildings is 16 °С.

7.5 If heat receivers in heating and ventilation systems do not have automatic individual temperature control devices inside the premises, heat carrier temperature control should be used in heat networks:

Central quality according to the heating load, according to the joint load of heating, ventilation and hot water supply - by changing the heat carrier temperature at the heat source depending on the outside air temperature;

central qualitative-quantitative for the joint load of heating, ventilation and hot water supply - by regulating both the temperature and the flow of network water at the heat source.

The central qualitative-quantitative regulation at the heat source can be supplemented by group quantitative regulation at heat points, mainly during the transition period of the heating season, starting from the break point of the temperature graph, taking into account the schemes for connecting heating, ventilation installations and hot water supply, pressure fluctuations in the heat supply system, the presence and locations of storage tanks, heat storage capacity of buildings and structures.

7.6 With the central qualitative and quantitative regulation of heat supply for heating water in hot water supply systems of consumers, the temperature of the water in the supply pipeline should be:

For closed heat supply systems - not less than 70 °С;

for open heat supply systems - at least 60 °C.

With central qualitative-quantitative regulation according to the combined load of heating, ventilation and hot water supply, the break point of the water temperature graph in the supply and return pipelines should be taken at the outside air temperature corresponding to the break point of the heating load control graph.

7.7 In heat supply systems, if the consumer has heat in the heating and ventilation systems of individual devices for controlling the indoor air temperature by the amount of water flowing through the network water receivers, central qualitative and quantitative regulation should be used, supplemented by group quantitative regulation at heating points in order to reduce fluctuations in hydraulic and thermal regimes in specific quarterly (microdistrict) systems within the limits that ensure the quality and stability of heat supply.

7.8 For separate water heating networks from one heat source to enterprises and residential areas, it is allowed to provide different heat carrier temperature charts.

7.9 In buildings for public and industrial purposes, for which a decrease in air temperature at night and during non-working hours is possible, regulation of the temperature or flow rate of the heat carrier in heat points should be provided.

7.10 In residential and public buildings, in the absence of thermostatic valves for heating devices, automatic control according to the temperature schedule should be provided to maintain the average temperature of the internal air in the building.

7.11 It is not allowed to use for heat networks the schedules for regulating the supply of heat "with cutoff" by temperature.

8 HYDRAULIC MODES

8.1 When designing new and reconstructing existing CHS, as well as when developing measures to improve the operational readiness and fail-safe operation of all parts of the system, the calculation of hydraulic modes is mandatory.

8.2 For water heating networks, the following hydraulic modes should be provided:

calculated - according to the estimated consumption of network water;

winter - at the maximum withdrawal of water for hot water supply from the return pipeline;

transitional - with maximum water withdrawal for hot water supply from the supply pipeline;

summer - at the maximum load of hot water supply in the non-heating period;

static - in the absence of coolant circulation in the heating network;

emergency.

8.3 Steam consumption in steam heating networks that provide enterprises with different daily operating modes should be determined taking into account the discrepancy between the maximum hourly steam consumption by individual enterprises.

For saturated steam pipelines, the total flow must take into account the additional amount of steam condensed due to heat losses in the pipelines.

8.4 The equivalent roughness of the inner surface of steel pipes should be taken:

for steam heat networks k_e = 0.0002 m;

for water heat networks k_e = 0.0005 m;

for hot water networks k_e = 0.001 m.

When pipelines made of other materials are used in heating networks, the values of equivalent roughness can be taken when confirming their actual value by testing, taking into account the service life.

8.5 The diameters of the supply and return pipelines of two-pipe water heating networks for the joint supply of heat for heating, ventilation and hot water supply are recommended to be taken the same.

8.6 The smallest inner diameter of pipes should be taken in heat networks at least 32 mm, and for hot water circulation pipelines - at least 25 mm.

8.7 Static pressure in heat supply systems with water as the heat carrier must be determined for a network water temperature of 100 °C. Under static conditions, an unacceptable increase in pressure in pipelines and equipment should be excluded.

8.8 The water pressure in the supply pipelines of water heating networks during the operation of network pumps should be taken based on the conditions of non-boiling water at its maximum temperature at any point in the supply pipeline, in the equipment of the heat source and in the devices of consumer systems directly connected to heating networks.

8.9 The water pressure in the return pipelines of water heating networks during the operation of network pumps must be excessive (at least 0.05 MPa) and 0.1 MPa below the allowable pressure in consumer heat use systems.

8.10 The water pressure in the return pipelines of water heat networks of open heat supply systems during the non-heating period, as well as in the supply and circulation pipelines of hot water supply networks, should be taken at least 0.05 MPa more than the static pressure of consumer hot water supply systems.

8.11 The pressure and temperature of the water at the suction pipes of the network, make-up, booster and mixing pumps should not be lower than the cavitation pressure and should not exceed the strength limits of the pump designs.

8.12 The head of the network pumps should be determined for the heating and non-heating periods and taken equal to the sum of the head losses in the installations at the heat source, in the supply and return pipelines from the heat source to the most remote consumer and in the consumer's system (including losses in heat points and pumping stations) with total estimated water consumption.

The pressure of booster pumps on the supply and return pipelines should be determined from piezometric graphs at maximum water flow rates in pipelines, taking into account hydraulic losses in equipment and pipelines.

8.13 The head of the make-up pumps should be determined from the conditions for maintaining static pressure in water heat networks and checked for the operating conditions of the network pumps during the heating and non-heating periods.

It is allowed to provide for the installation of separate groups of make-up pumps with different heads for the heating, non-heating periods and for the static mode.

8.14 The supply (capacity) of working make-up pumps at the heat source in closed heat supply systems should be taken equal to the water flow to compensate for network water losses from the heat network, and in open systems - equal to the sum of the maximum water flow for hot water supply and water flow to compensate for losses.

8.15 The head of the mixing pumps should be determined by the largest pressure difference between the supply and return pipelines.

8.16 The number of pumps should be taken:

network - at least two, one of which is a backup; with five working network pumps in one group, the standby pump may not be installed;

Booster and mixing (in heat networks) - at least three, one of which is a backup, while a backup pump is provided regardless of the number of working pumps;

make-up - in closed heat supply systems at least two, one of which is a reserve, in open systems - at least three, one of which is also a reserve;

at the nodes of dividing the water heating network into zones (at the nodes of the cut), it is allowed to install one make-up pump without a reserve in closed heat supply systems, and one working and one standby pump in open systems.

The number of pumps is determined taking into account their joint work on the heating network.

8.17 When determining the pressure of network pumps, the pressure drop at the input of two-pipe water heating networks to buildings (with elevator connection of heating systems) should be taken equal to the calculated pressure loss at the input and in the local system with a coefficient of 1.5, but not less than 0.15 MPa. It is recommended to extinguish excess pressure in the heating points of buildings.

8.18 When designing CHS with a heat consumption of more than 100 MW, it is necessary to determine the need for an integrated protection system that prevents the occurrence of hydraulic shocks and unacceptable pressures in the equipment of water heating installations of heat sources, in heat networks, and consumer heat use systems.

9 ROUTE AND METHODS OF LAYING HEAT NETWORKS

9.1 In settlements, for heating networks, as a rule, underground laying is provided (without channels, in channels or in city and intra-block tunnels together with other engineering networks).

When justified, above-ground laying of heating networks is allowed, except for the territories of children's and medical institutions.

9.2 The laying of heat networks on the territory not subject to development outside settlements should be provided above ground on low supports.

The laying of heat networks on embankments of public roads of categories I, II and III is not allowed.

9.3 When choosing a route, it is allowed to intersect residential and public buildings with transit water heating networks with diameters of heat pipes up to 300 mm inclusive, provided that networks are laid in technical undergrounds and tunnels (at least 1.8 m high) with a drainage well at the lowest point at the exit from the building .

As an exception, it is allowed to cross transit water heating networks with a diameter of 400 - 600 mm, pressure Р_у<= 1,6 МПа жилых и общественных зданий при соблюдении следующих требований:

the laying should be provided in monolithic reinforced concrete through channels with reinforced waterproofing. The ends of the channel must extend beyond the building by at least 5 m;

water outlets with a diameter of 300 mm should be carried out from the lower points of the channel outside the building to the storm sewer;

During installation, a 100% check of the welds of steel pipes of heat pipelines is mandatory;

Shut-off and control valves should be installed outside the building;

heat pipelines within the building should not have branches.

Crossing by transit heat networks of buildings and structures of preschool, school and medical institutions is not allowed. The laying of heating networks on the territory of the listed institutions is allowed only underground in monolithic reinforced concrete channels with waterproofing. At the same time, the installation of ventilation shafts, hatches and exits to the outside from the channels within the territory of institutions is not allowed, shutoff valves must be installed outside the territory.

9.4 Laying of heating networks at a working steam pressure above 2.2 MPa and a temperature above 350 ° C in tunnels together with other engineering networks is not allowed.

9.5 The slope of heating networks, regardless of the direction of movement of the coolant and the method of laying, must be at least 0.002. With roller and ball bearings, the slope should not exceed

(1)

Where r is the radius of the roller or ball, see

The slope of heating networks to individual buildings during underground laying should, as a rule, be taken from the building to the nearest chamber.

In some areas (when crossing communications, laying on bridges, etc.), it is allowed to accept the laying of heat networks without a slope.

9.6 Underground laying of heat networks is allowed to be provided together with the engineering networks listed below:

in channels - with water pipelines, compressed air pipelines with a pressure of up to 1.6 MPa, fuel oil pipelines, control cables intended for servicing heating networks;

in tunnels - with water pipes up to 500 mm in diameter, communication cables, power cables with voltage up to 10 kV, compressed air pipelines with pressure up to 1.6 MPa, pressure sewer pipelines.

Laying of pipelines of heating networks in channels and tunnels with other engineering networks, except for those indicated, is not allowed.

The laying of pipelines for heating networks should be provided in one row or above other engineering networks.

9.7 Horizontal and vertical distances from the outer edge of the building structures of channels and tunnels or the pipeline insulation shell during channelless laying of heat networks to buildings, structures and engineering networks should be taken in accordance with Appendix B. When laying heat pipelines through the territory of industrial enterprises - according to the relevant specialized standards.

9.8 The crossing of rivers, highways, tram lines, as well as buildings and structures by heating networks should, as a rule, be provided at a right angle. It is allowed, when justified, to cross at a smaller angle, but not less than 45 °, and for subway and railway structures - not less than 60 °.

9.9 The crossing of tram tracks by underground heating networks should be provided at a distance of at least 3 m from switches and crosses (clearly).

9.10 At underground crossing of railways by heating networks, the smallest horizontal distances in the light should be taken, m:

up to the points and crosses of the railway track and the places where suction cables are connected to the rails of electrified railways - 10;

to arrows and crosses of the railway track with subsiding soils - 20;

to bridges, pipes, tunnels and other artificial structures - 30.

9.11 The laying of heat networks at the intersection of railways of the general network, as well as rivers, ravines, open drains, should be provided, as a rule, above ground. In this case, it is allowed to use permanent road and railway bridges.

The laying of heat networks at the underground intersection of railways, highways, main roads, streets, driveways of citywide and regional significance, as well as streets and roads of local importance, tram tracks and metro lines should be provided for:

in channels - if it is possible to carry out construction, installation and repair work in an open way;

In cases - if it is impossible to perform work in an open way, the length of the intersection is up to 40 m;

In tunnels - in other cases, as well as when deepening from the surface of the earth to the top of the pipeline is 2.5 m or more.

When laying heating networks under water barriers, as a rule, siphons should be provided.

The intersection of heating networks with metro station structures is not allowed.

At underground crossing of metro lines by heating networks, channels and tunnels should be provided from monolithic reinforced concrete with waterproofing.

9.12 The length of channels, tunnels or cases at intersections must be taken in each direction by at least 3 m more than the dimensions of the structures being crossed, including the subgrade structures of railways and roads, taking into account Table B.3.

When heating networks cross railways of the general network, metro lines, rivers and reservoirs, shut-off valves should be provided on both sides of the intersection, as well as devices for draining water from pipelines of heating networks, channels, tunnels or cases at a distance of not more than 100 m from the border of the structures being crossed .

9.13 When laying heat networks in cases, anti-corrosion protection of pipes of heat networks and cases should be provided. At the intersection of electrified railways and tramways, electrochemical protection should be provided.

A gap of at least 100 mm must be provided between the thermal insulation and the case.

9.14 At the intersections during underground laying of heat networks with gas pipelines, it is not allowed to pass gas pipelines through the building structures of chambers, impassable channels and tunnels.

9.15 When heating networks intersect water supply and sewerage networks located above the pipelines of heating networks, when the distance from the structure of the heating networks to the pipelines of the intersected networks is 300 mm or less (in the light), as well as when crossing gas pipelines, it is necessary to provide for the installation of cases on pipelines of water supply, sewerage and gas at a length of 2 m on both sides of the intersection (in the light). Cases should be provided with a protective coating against corrosion.

9.16 At the intersections of heat networks during their underground laying in channels or tunnels with gas pipelines, devices for sampling for gas leakage should be provided on heat networks at a distance of no more than 15 m on both sides of the gas pipeline.

When laying heat networks with associated drainage at the intersection with the gas pipeline, drainage pipes should be provided without holes at a distance of 2 m on both sides of the gas pipeline, with sealed joints.

9.17 At the inlets of pipelines of heating networks into buildings in gasified areas, it is necessary to provide devices that prevent the penetration of water and gas into buildings, and in non-gasified areas - water.

9.18 At the intersection of above-ground heat networks with overhead power lines and electrified railways, grounding of all electrically conductive elements of heat networks (with a resistance of grounding devices of not more than 10 ohms) located at a horizontal distance of 5 m in each direction from the wires should be provided.

9.19 Laying of heating networks along the edges of terraces, ravines, slopes, artificial cuts should be provided outside the prism of soil collapse from soaking. At the same time, when buildings and structures for various purposes are located under a slope, measures should be taken to divert emergency water from heating networks in order to prevent flooding of the building area.

9.20 In the area of heated pedestrian crossings, including those combined with subway entrances, it is necessary to provide for the laying of heating networks in a monolithic reinforced concrete channel extending 5 m beyond the crossing clearance.

10 PIPING DESIGN

10.1 Pipes, fittings and products made of steel and cast iron for heating networks should be taken in accordance with the rules for the design and safe operation of steam and hot water pipelines PB 10-573 of the Gosgortekhnadzor of Russia. The calculation of steel and cast iron pipelines for strength should be carried out according to the standards for calculating the strength of pipelines of heat networks RD 10-400 and RD 10-249.

10.2 For pipelines of heat networks, electric-welded steel pipes or seamless steel pipes should be provided.

Ductile iron pipes with nodular graphite (VCSHG) are allowed to be used for heating networks at water temperatures up to 150 ° C and pressures up to 1.6 MPa inclusive.

10.3 For pipelines of heat networks at an operating steam pressure of 0.07 MPa and below and a water temperature of 115 ° C and below at a pressure of up to 1.6 MPa inclusive, it is allowed to use non-metallic pipes if the quality and characteristics of these pipes meet sanitary requirements and correspond to the parameters of the heat carrier in thermal networks.

10.4 For hot water supply networks in closed heat supply systems, pipes made of corrosion-resistant materials or coatings should be used. Pipes made of ductile iron, polymeric materials and non-metallic pipes can be used for both closed and open heat supply systems.

10.5 The maximum distances between the movable pipe supports in straight sections should be determined by strength calculation, based on the possibility of maximizing the bearing capacity of the pipes and according to the allowable deflection, taken no more than 0.02 D_u, m.

10.6 For the selection of pipes, fittings, equipment and parts of pipelines, as well as for calculating pipelines for strength and when determining the loads from pipelines on pipe supports and building structures, the working pressure and temperature of the coolant should be taken:

a) for steam networks:

When receiving steam directly from the boilers - according to the nominal values of the pressure and temperature of the steam at the outlet of the boilers;

When steam is received from controlled extractions or backpressure of turbines - according to the pressure and temperature of the steam, taken at the outlets from the CHP for this system of steam pipelines;

upon receipt of steam after reduction-cooling, reduction or cooling installations (ROU, RU, OS) - according to the pressure and temperature of the steam after installation;

b) for the supply and return pipelines of water heating networks:

pressure - according to the highest pressure in the supply pipeline behind the outlet valves on the heat source when the network pumps are operating, taking into account the terrain (without taking into account pressure losses in the networks), but not less than 1.0 MPa;

Temperature - according to the temperature in the supply pipeline at the calculated outdoor air temperature for heating design;

c) for condensate networks:

pressure - according to the highest pressure in the network when the pumps are operating, taking into account the terrain;

temperature after steam traps - according to the saturation temperature at the maximum possible steam pressure immediately before the steam trap, after condensate pumps - according to the temperature of the condensate in the collection tank;

D) for the supply and circulation pipelines of hot water supply networks:

Pressure - according to the highest pressure in the supply pipeline during pump operation, taking into account the terrain;

temperature - up to 75 °C.

10.7 The operating pressure and temperature of the heat carrier must be taken as the same for the entire pipeline, regardless of its length from the heat source to the heating point of each consumer or to installations in the heat network that change the parameters of the heat carrier (water heaters, pressure and temperature regulators, reduction and cooling units, pumping stations) . After these settings, the coolant parameters provided for these installations should be accepted.

10.8 The parameters of the coolant of the reconstructed water heating networks are taken according to the parameters in the existing networks.

10.9 For pipelines of heating networks, except for heating points and hot water supply networks, it is not allowed to use fittings from:

gray cast iron - in areas with an estimated outdoor air temperature for heating design below minus 10 ° C;

ductile iron - in areas with an estimated outdoor temperature for heating design below minus 30 ° C;

Ductile iron in areas with an estimated outdoor temperature for heating design below minus 40 °C.

It is not allowed to use fittings made of gray cast iron on drain, purge and drainage devices.

It is allowed to use fittings made of brass and bronze on pipelines of heating networks at a coolant temperature not exceeding 250 °C.

At the outlets of heat networks from heat sources and at the inlets to central heating points (CHP), steel shut-off valves should be provided.

At the input to an individual heating point (ITP) with a total heat load on heating and ventilation of 0.2 MW or more, steel shut-off valves should be provided. When the IHF load is less than 0.2 MW or the calculated coolant temperature is 115 °C and below, it is allowed to provide fittings made of malleable or ductile iron at the inlet.

Within the thermal points, it is allowed to provide fittings made of malleable, high-strength and gray cast iron in accordance with PB 10-573.

10.10 When installing cast iron fittings in heating networks, it must be protected from bending forces.

10.11 It is not allowed to accept shut-off valves as control valves.

10.12 For heating networks, as a rule, fittings with weld ends or flanged ones should be accepted.

Coupling fittings are allowed to be accepted with nominal diameter D_y<= 100 мм при давлении теплоносителя 1,6 МПа и ниже и температуре 115 °С и ниже в случаях применения водогазопроводных труб.

10.13 For valves and gates on water heat networks with a diameter D_y >= 500 mm at a pressure Р_у >= 1.6 MPa and D_y >= 300 mm at Р_у>= 2.5 MPa, and on steam networks D_y>= 200 mm at Р_у >= 1.6 MPa, bypass pipelines with shut-off valves (unloading bypasses) should be provided.

10.14 Gate valves and gates D_y>= 500 mm should be provided with an electric drive.

In case of remote remote control of gate valves, fittings on bypasses should also be taken with an electric drive.

10.15 Gate valves and gates with an electric drive during underground laying should be placed in chambers with above-ground pavilions or in underground chambers with natural ventilation, providing air parameters in accordance with the specifications for electric drives to valves.

When laying above-ground heating networks on low supports, for valves and gates with an electric drive, metal casings should be provided to exclude access by unauthorized persons and protect them from atmospheric precipitation, and on transit highways, as a rule, pavilions. When laying on overpasses or high free-standing supports - canopies (canopies) to protect the reinforcement from precipitation.

10.16 In construction areas with an estimated outdoor air temperature of minus 40 °С and below, when carbon steel reinforcement is used, measures should be taken to exclude the possibility of reducing the steel temperature below minus 30 °С during transportation, storage, installation and operation, and when laying heating networks on low supports for valves and gates D_y >= 500 mm, pavilions with electric heating should be provided, which excludes the decrease in air temperature in the pavilions below minus 30 ° C when the networks stop.

10.17 Shut-off valves in heat networks should be provided for:

a) on all pipelines of heat networks outlets from heat sources, regardless of the parameters of the heat carrier and diameters of pipelines, and on condensate pipelines at the inlet to the condensate collection tank; at the same time, duplication of reinforcement inside and outside the building is not allowed;

B) on pipelines of water heating networks D_y >= 100 mm at a distance of no more than 1000 m from each other (sectional valves) with a jumper between the supply and return pipelines with a diameter equal to 0.3 of the pipeline diameter, but not less than 50 mm; on the jumper it is necessary to provide two valves and a control valve between them D_y = 25 mm.

It is allowed to increase the distance between sectional valves for pipelines D_y = 400 - 500 mm - up to 1500 m, for pipelines D_y >= 600 mm - up to 3000 m, and for pipelines of above-ground laying D_y >= 900 mm - up to 5000 m while ensuring the draining of water and filling a sectioned section of one pipeline for a time not exceeding that specified in 10.19.

Sectional valves may not be installed on steam and condensate heating networks.

c) in water and steam heating networks in nodes on branch pipelines D_y more than 100 mm.

10.18 At the lower points of pipelines of water heat networks and condensate pipelines, as well as sectioned sections, it is necessary to provide fittings with shutoff valves for draining water (drainage devices).

10.19 Drain devices of water heat networks should be provided based on ensuring the duration of water drain and filling of a sectioned section (one pipeline), h:

for pipelines D_y<= 300 мм - не более 2;

D_y \u003d 350 - 500 the same 4;

D_y >= 600 "5.

If the discharge of water from pipelines at low points is not ensured within the specified periods, intermediate discharge devices must be additionally provided.

10.20 Mud pans in water heating networks should be provided on pipelines in front of pumps and in front of pressure regulators in cut-off units. It is not required to provide mudguards in the installation units of sectional valves.

10.21 The arrangement of bypass pipelines around sumps and control valves is not allowed.

10.22 At the highest points of pipelines of heat networks, including at each sectioned section, fittings with shut-off valves for air release (air vents) should be provided.

In pipeline nodes on branches to valves and in local bends of pipelines with a height of less than 1 m, air outlet devices may not be provided.

10.23 Drainage of water from pipelines at the lowest points of water heating networks during underground laying should be provided separately from each pipe with a jet break into waste wells, followed by water discharge by gravity or mobile pumps into the sewerage system. The temperature of the discharged water must be reduced to 40 °C.

Descent of water directly into the chambers of heating networks or onto the surface of the earth is not allowed. When laying pipelines above ground in an undeveloped area, water can be drained into concrete pits with water drained from them by cuvettes, trays or pipelines.

It is allowed to provide for the drainage of water from waste wells or pits to natural reservoirs and to the terrain, subject to agreement with the supervisory authorities.

When draining water into a domestic sewer, a non-return valve must be provided on a gravity pipeline in case of a possibility of a reverse flow of water.

It is allowed to drain water directly from one section of the pipeline to the adjacent section, as well as from the supply pipeline to the return one.

10.24 At the low points of steam networks and in front of vertical rises, permanent drainage of steam pipelines should be provided. In the same places, as well as on straight sections of steam pipelines, starting drainage of steam pipelines should be provided every 400 - 500 m with a passing slope and every 200 - 300 m with an opposite slope.

10.25 For start-up drainage of steam networks, fittings with shut-off valves should be provided.

At each fitting at an operating steam pressure of 2.2 MPa or less, one valve or valve should be provided; at an operating steam pressure above 2.2 MPa - two valves in series.

10.26 For permanent drainage of steam networks or when combining permanent drainage with a start-up one, fittings with plugs and steam traps connected to the fitting through a drainage pipeline shall be provided.

When laying several steam pipelines, a separate steam trap must be provided for each of them (including those with the same steam parameters).

10.27 Discharge of condensate from permanent drains of steam networks to a pressure condensate pipeline is allowed provided that at the point of connection the condensate pressure in the drainage condensate pipeline exceeds the pressure in the pressure condensate pipeline by at least 0.1 MPa; in other cases, condensate discharge is provided outside. Special condensate pipelines for condensate discharge are not provided.

10.28 To compensate for thermal deformations of pipelines of heat networks, the following compensation methods and compensating devices should be used:

flexible compensators (of various shapes) made of steel pipes and the angles of turns of pipelines - for any parameters of the coolant and laying methods;

bellows and lens compensators - for coolant parameters and laying methods in accordance with the technical documentation of manufacturers;

Starting compensators designed to partially compensate for thermal deformations due to changes in axial stress in a pinched pipe;

gland steel compensators with coolant parameters Р_у<= 2,5 МПа и t<= 300 °С для трубопроводов диаметром 100 мм и более при подземной прокладке и надземной на низких опорах.

It is allowed to use non-compensating gaskets when the compensation of temperature deformations is fully or partially carried out due to alternating changes in axial compressive and tensile stresses in the pipe. A buckling test is required.

10.29 When laying above ground, metal casings should be provided to exclude access to stuffing box compensators by unauthorized persons and protect them from atmospheric precipitation.

10.30 The installation of movement indicators to monitor thermal elongation of pipelines in heating networks, regardless of the parameters of the coolant and the diameters of pipelines, is not required.

10.31 For heat networks, as a rule, factory-made parts and elements of pipelines should be accepted.

For flexible expansion joints, bending angles and other bent elements of pipelines, factory-made steeply bent bends with a bend radius of at least one pipe diameter should be accepted.

For pipelines of water heating networks with a working pressure of the coolant up to 2.5 MPa and a temperature of up to 200 ° C, as well as for steam heating networks with an operating pressure of up to 2.2 MPa and a temperature of up to 350 ° C, it is allowed to accept welded sector bends.

Stamp-welded tees and bends are allowed to be accepted for coolants of all parameters.

Notes

1. Stamp-welded and welded sector bends are allowed to be accepted subject to 100% control of the welded joints of the bends by ultrasonic flaw detection or radiation transillumination.

2. Welded sector bends are allowed to be accepted provided that they are manufactured with an internal underwelding of welds.

3. It is not allowed to manufacture pipeline parts, including bends, from electric-welded pipes with a spiral seam.

4. Welded sector bends for pipelines made of ductile iron pipes are allowed to be accepted without internal welding of welds, if the formation of a reverse bead is ensured, and lack of penetration in depth does not exceed 0.8 mm for a length of not more than 10% of the length of the weld at each joint.

10.32 The distance between adjacent welds on straight sections of pipelines with coolant pressure up to 1.6 MPa and temperature up to 250 °C must be at least 50 mm, for coolants with higher parameters - at least 100 mm.

The distance from the transverse weld to the beginning of the bend must be at least 100 mm.

10.33 Steeply curved bends may be welded together without a straight section. It is not allowed to weld sharply bent and welded bends directly into the pipe without a fitting (pipe, branch pipe).

10.34 Movable pipe supports should be provided for:

Sliding - regardless of the direction of horizontal movements of pipelines for all methods of laying and for all pipe diameters;

roller - for pipes with a diameter of 200 mm or more with axial movement of pipes when laying in tunnels, on brackets, on free-standing supports and overpasses;

ball - for pipes with a diameter of 200 mm or more with horizontal movements of pipes at an angle to the axis of the route when laying in tunnels, on brackets, on free-standing supports and overpasses;

Spring supports or suspensions - for pipes with a diameter of 150 mm or more in places of vertical movement of pipes;

Rigid hangers - for above-ground laying of pipelines with flexible compensators and in self-compensation areas.

Note - In sections of pipelines with stuffing box and axial bellows compensators, it is not allowed to provide for laying pipelines on suspension supports.

10.35 The length of rigid hangers should be taken for water and condensate heat networks at least ten times, and for steam networks - at least twenty times the thermal displacement of the pipe with the hanger, the furthest from the fixed support.

10.36 Axial bellows expansion joints (SC) are installed indoors, in passage channels. It is allowed to install the SC outdoors and in thermal chambers in a metal shell that protects the bellows from external influences and pollution.

Axial bellows compensating devices (SKU) (bellows compensators protected from pollution, external influences and transverse loads by a strong casing) can be used for all types of laying.

SK and SKU can be placed anywhere in the heat pipeline between fixed supports or conditionally fixed pipe sections, if there are no restrictions from the manufacturer.

When choosing a location, it must be possible to shift the compensator casing in any direction to its full length.

10.37 When using SC and SKU on heat pipelines for underground laying in channels, tunnels, chambers, for above-ground laying and indoors, it is mandatory to install guide supports.

When installing the starting compensators, guide supports are not installed.

10.38 Guiding supports should be used, as a rule, of an enclosing type (clamp, tubular, frame), forcibly limiting the possibility of transverse shear and not preventing axial movement of the pipe.

10.39 Requirements for the placement of pipelines when they are laid in impassable channels, tunnels, chambers, pavilions, for above-ground laying and at heat points are given in Appendix B.

10.40 The technical characteristics of expansion joints must satisfy the calculation of the strength in cold and in working condition of pipelines.

10.41 Heat pipelines with channelless laying should be checked for stability (longitudinal bending) in the following cases:

At a shallow depth of laying of heat pipelines (less than 1 m from the pipe axis to the ground surface);

if the heat pipeline is likely to be flooded with ground, flood or other waters;

with the likelihood of conducting earthworks near the heating main.

11 THERMAL INSULATION

11.1 For heat networks, as a rule, heat-insulating materials and structures that have been proven by operational practice should be adopted. New materials and designs are allowed for use subject to positive results of independent tests conducted by specialized laboratories.

11.2 The materials of thermal insulation and the cover layer of heat pipelines must meet the requirements of SNiP 41-03, fire safety standards and be selected depending on the specific conditions and methods of laying.

When joint underground laying in tunnels (passage channels) of heat pipelines with electric or low-current cables, pipelines transporting combustible substances, it is not allowed to use a thermal insulating structure made of combustible materials. In case of separate laying of heat pipelines in tunnels (passage channels), the use of non-combustible materials (NG) is mandatory only for the cover layer of thermal insulation of heat pipelines.

For underground channelless laying and in impassable channels, it is allowed to use combustible materials of heat-insulating and cover layers.

11.3 The tunnel (passage channel) should be divided every 200 m into compartments by fire partitions of the 1st type with fire doors of the 2nd type.

11.4 When laying heat pipelines in thermal insulation made of combustible materials, inserts made of non-combustible materials with a length of at least 3 m should be provided:

in each chamber of the heating network and at the entrance to buildings;

for above-ground laying - every 100 m, while for vertical sections every 10 m;

in places where heat pipes exit from the ground.

When using heat pipeline structures in thermal insulation made of combustible materials in a non-combustible shell, it is allowed not to make inserts.

11.5 Details of fastening of heat pipelines must be made of corrosion-resistant materials or covered with anti-corrosion coatings.

11.6 The choice of thermal insulation material and the design of the heat pipeline should be made according to the economic optimum of the total operating costs and investments in heat networks, related structures and facilities. When choosing heat-insulating materials, the use of which causes the need to change the parameters of the coolant (design temperature, control modes, etc.), it is necessary to compare the options for district heating systems as a whole.

The choice of thermal insulation thickness should be made according to SNiP 41-03 for the specified parameters, taking into account the climatological data of the construction site, the cost of the thermal insulation structure and heat.

11.7 When determining heat losses by pipelines, the design temperature of the heat carrier is taken for the supply heat pipelines of water heat networks:

at a constant temperature of network water and quantitative regulation - the maximum temperature of the heat carrier;

with a variable temperature of network water and high-quality regulation - the average annual temperature of the heat carrier is 110 °С with a temperature control schedule of 180 - 70 °С, 90 °С at 150 - 70 °С, 65 °С at 130 - 70 °С and 55 °С at 95 - 70 °C. The average annual temperature for the return heat pipelines of water heat networks is assumed to be 50 °C.

11.8 When placing heat pipelines in office premises, technical undergrounds and basements of residential buildings, the temperature of the internal air is assumed to be 20 °C, and the temperature on the surface of the heat pipeline structure is not higher than 45 °C.

11.9 When choosing the designs of heat pipelines above ground and channel laying, the requirements for heat pipelines in the assembly should be observed:

When using structures with non-hermetic coatings, the cover layer of thermal insulation must be waterproof and not prevent the moistened thermal insulation from drying out;

when using structures with sealed coatings, it is mandatory to install a system for operational remote control (ODC) of moistening thermal insulation;

indicators of temperature resistance, insolation resistance must be within the specified limits during the entire estimated service life for each element or structure;

11.10 When choosing designs for underground channelless laying of heat networks, two groups of heat pipeline designs should be considered:

group "a" - heat pipes in a sealed vapor-tight waterproof shell. Representative design - factory-made heat pipes in polyurethane foam insulation with a polyethylene sheath according to GOST 30732;

group "b" - heat pipelines with a vapor-permeable waterproof coating or in monolithic thermal insulation, the outer compacted layer of which must be waterproof and vapor-permeable at the same time, and the inner layer adjacent to the pipe must protect the steel pipe from corrosion. Representative structures - prefabricated heat pipes in foam-polymer-mineral or armor-foam-concrete thermal insulation.

11.11 Mandatory requirements for heat pipelines of group "a":

uniform filling density of the structure with heat-insulating material;

the tightness of the shell and the presence of the ODK system, the organization of the replacement of the wet area with a dry one;

the rate of external corrosion of pipes should not exceed 0.03 mm/year;

Abrasion resistance of the protective coating - for more than 2 mm / 25 years.

Mandatory requirements for the physical and technical characteristics of the structures of heat pipelines of group "b":

temperature resistance indicators must be within the specified limits during the estimated service life;

the rate of external corrosion of steel pipes should not exceed 0.03 mm/year.

11.12 When calculating the insulation thickness and determining the annual heat losses by heat pipelines laid without channels at a depth of the heat pipeline axis of more than 0.7 m, the yearly average soil temperature at this depth is taken as the design ambient temperature.

When the depth of the heat pipeline from the top of the heat-insulating structure is less than 0.7 m, the same ambient temperature is taken as the design ambient temperature as in the case of above-ground laying.

To determine the soil temperature in the temperature field of an underground heat pipeline, the temperature of the heat carrier must be taken:

for water heating networks - according to the temperature regulation schedule at the average monthly temperature of the outside air of the settlement month;

For hot water networks - according to the maximum temperature of hot water.

11.13 When choosing the structures of above-ground heat pipelines, the following requirements for the physical and technical characteristics of the structures of heat pipelines should be taken into account:

temperature resistance indicators should be within the specified limits during the estimated service life of the structure;

the rate of external corrosion of steel pipes should not exceed 0.03 mm/year.

11.14 When determining the thickness of the thermal insulation of heat pipelines laid in through channels and tunnels, the air temperature in them should not exceed 40 °C.

11.15 When determining annual heat losses by heat pipelines laid in channels and tunnels, the heat carrier parameters should be taken according to 11.7.

11.16 When laying heating networks in impassable channels and without channels, the thermal conductivity coefficient of thermal insulation should be taken into account, taking into account possible moisture in the design of heat pipelines.

12 BUILDING STRUCTURES

12.1 Frames, brackets and other steel structures for pipelines of heating networks must be protected from corrosion.

12.2 For the external surfaces of channels, tunnels, chambers and other structures, when laying heat networks outside the groundwater level zone, coating insulation and adhesive waterproofing of the ceilings of these structures should be provided.

12.3 When laying heating networks in channels below the maximum standing groundwater level, associated drainage should be provided, and for the outer surfaces of building structures and embedded parts - waterproofing insulation.

If it is not possible to use associated drainage, gluing waterproofing should be provided to a height exceeding the maximum groundwater level by 0.5 m, or other effective waterproofing.

When channelless laying of heat pipelines with a polyethylene cover layer, the associated drainage device is not required.

12.4 For associated drainage, pipes with prefabricated elements, as well as ready-made pipe filters, should be accepted. The diameter of the drainage pipes must be taken into account.

12.5 At angles of rotation and on straight sections of associated drainages, it is necessary to provide for the construction of manholes at least every 50 m.

12.6 To collect water, a reservoir with a capacity of at least 30% of the maximum hourly amount of drainage water should be provided.

The drainage of water from the associated drainage system should be provided by gravity or by pumping into rain sewers, reservoirs or ravines.

12.7 To pump out water from the associated drainage system, at least two pumps should be installed in the pump room, one of which is a standby one. The supply (capacity) of the working pump should be taken in terms of the maximum hourly amount of incoming water with a factor of 1.2, taking into account the removal of random water.

12.8 The slope of associated drainage pipes shall be taken as not less than 0.003.

12.9 The design of shield fixed supports should be accepted only with an air gap between the pipeline and the support and allow the possibility of replacing the pipeline without destroying the reinforced concrete body of the support. In the shield supports, holes should be provided to ensure the flow of water, and, if necessary, holes for ventilation of the channels.

12.10 The height of the passage channels and tunnels must be at least 1.8 m. The width of the passages between the heat pipes must be equal to the outer diameter of the uninsulated pipe plus 100 mm, but not less than 700 mm. The clear height of the chambers from the floor level to the bottom of the protruding structures should be taken at least 2 m. Local reduction of the chamber height to 1.8 m is allowed.

12.11 For tunnels, entrances with ladders should be provided at a distance of no more than 300 m from each other, as well as emergency and entrance hatches at a distance of no more than 200 m for water heating networks.

Entrance hatches should be provided at all end points of dead-end sections of tunnels, at turns and at nodes where, according to the layout conditions, pipelines and fittings impede passage.

12.12 In tunnels, at least every 300 m, installation openings should be provided with a length of at least 4 m and a width of at least the largest diameter of the pipe being laid plus 0.1 m, but not less than 0.7 m.

12.13 The number of hatches for the chambers should be at least two located diagonally.

12.14 From the pits of the chambers and tunnels at the lower points, gravity drainage of random waters into waste wells and the installation of shut-off valves at the inlet of the gravity pipeline to the well should be provided. Water drainage from the pits of other chambers (not at the lower points) should be provided by mobile pumps or directly by gravity into the sewerage system with a device on the gravity pipeline of the water seal, and if the water can be reversed, additional shut-off valves.

12.15 It is necessary to provide supply and exhaust ventilation in tunnels. Tunnel ventilation should ensure both in winter and summer the air temperature in the tunnels is not higher than 40 ° C, and during the repair work - not higher than 33 ° C. The air temperature in tunnels can be reduced from 40 to 33 °C using mobile ventilation units.

The need for natural ventilation channels is established in the projects. When using materials for thermal insulation of pipes that emit harmful substances during operation in quantities exceeding the MPC in the air of the working area, a ventilation device is mandatory.

12.16 Ventilation shafts for tunnels may be combined with their entrances. The distance between the supply and exhaust shafts should be determined by calculation.

12.17 In case of channelless laying of heat networks, heat pipelines are laid on a sandy base with a bearing capacity of soils of at least 0.15 MPa. In weak soils with a bearing capacity of less than 0.15 MPa, an artificial foundation is recommended.

12.18 Channelless laying of heat pipelines can be designed under the impassable part of streets and inside residential areas, under streets and roads of category V and local significance. Laying of heat pipelines under the carriageway of motor roads of categories I - IV, main roads and streets is allowed in channels or cases.

12.19 At the underground crossing of roads and streets, the requirements set forth in Appendix B must be observed.

12.20 When compensating for thermal expansion due to the angles of rotation of the route, U-shaped, L-shaped, Z-shaped compensators for channelless laying of pipelines, shock-absorbing gaskets or channels (niches) should be provided.

Branches that are not located at fixed supports should also be provided with shock-absorbing pads.

13 PROTECTION OF PIPING AGAINST CORROSION

13.1 When choosing a method for protecting steel pipes of heating networks from internal corrosion and schemes for preparing make-up water, the following main parameters of network water should be taken into account:

hardness of water;

Hydrogen indicator pH;

13.2 Protection of pipes from internal corrosion should be carried out by:

reducing the oxygen content in network water;

coating the inner surface of steel pipes with anti-corrosion compounds or the use of corrosion-resistant steels;

application of a reagentless electrochemical method of water treatment;

application of water treatment and deaeration of make-up water;

use of corrosion inhibitors.

13.3 To control internal corrosion on the supply and return pipelines of water heating networks, installation of corrosion indicators should be provided at the outlets from the heat source and in the most typical places.

14 HEAT POINTS

14.1 Heat points are subdivided into:

individual heating points (ITP) - for connecting heating, ventilation, hot water supply systems and technological heat-using installations of one building or its part;

Central heating points (CHP) - the same, two buildings or more.

14.2 The heating points provide for the placement of equipment, fittings, control, management and automation devices, through which the following are carried out:

conversion of the type of coolant or its parameters;

control of coolant parameters;

accounting for thermal loads, coolant and condensate flow rates;

regulation of heat carrier flow and distribution to heat consumption systems (through distribution networks in central heating stations or directly to ITP systems);

Protection of local systems from emergency increase in coolant parameters;

filling and make-up of heat consumption systems;

Collection, cooling, return of condensate and control of its quality;

heat storage;

water treatment for hot water systems.

In a thermal point, depending on its purpose and local conditions, all of the listed activities or only part of them can be carried out. Devices for monitoring the parameters of the coolant and accounting for heat consumption should be provided in all heating points.

14.3 The input ITP device is mandatory for each building, regardless of the presence of the central heating point, while the ITP provides only those measures that are necessary for connecting this building and are not provided for in the central heating point.

14.4 In closed and open heat supply systems, the need for a central heating station for residential and public buildings must be justified by a feasibility study.

14.5 It is allowed to place equipment of sanitary systems of buildings and structures, including booster pumping units that supply water for household and drinking and fire fighting needs, in the premises of heat points.

14.6 The basic requirements for the placement of pipelines, equipment and fittings in heating points should be adopted according to Appendix B.

14.7 The connection of heat consumers to heat networks in heat points should be provided according to schemes that ensure the minimum water consumption in heat networks, as well as heat savings through the use of heat flow regulators and limiters for the maximum flow of network water, corrective pumps or elevators with automatic control that reduce the temperature water entering the heating, ventilation and air conditioning systems.

14.8 The design water temperature in the supply pipelines after the CHP should be taken:

when connecting heating systems of buildings according to a dependent scheme - equal, as a rule, to the calculated water temperature in the supply pipeline of heating networks to the central heating station;

with an independent circuit - no more than 30 ° C lower than the calculated water temperature in the supply pipeline of heat networks to the CHP, but not higher than 150 ° C and not lower than the calculated temperature adopted in the consumer's system.

Independent pipelines from the central heating station for connecting ventilation systems with an independent connection scheme for heating systems are provided for with a maximum heat load on ventilation of more than 50% of the maximum heat load on heating.

14.9 When calculating the heating surface of water-to-water water heaters for hot water supply and heating systems, the water temperature in the supply pipeline of the heating network should be taken equal to the temperature at the break point of the water temperature graph or the minimum water temperature, if there is no break in the temperature graph, and for heating systems - also the temperature water corresponding to the calculated outdoor temperature for heating design. The largest of the obtained values of the heating surface should be taken as the calculated one.

14.10 When calculating the heating surface of hot water supply water heaters, the temperature of the heated water at the outlet from the water heater to the hot water supply system should be assumed to be at least 60 °C.

14.11 For high-speed sectional water-to-water water heaters, a countercurrent scheme of heat carrier flows should be adopted, while heating water from the heating network should flow:

in water heaters of heating systems - in tubes;

The same, hot water supply - in the annulus.

In steam-water water heaters, steam must enter the annulus.

For hot water supply systems with steam heating networks, it is allowed to use capacious water heaters, using them as hot water storage tanks, provided that their capacity corresponds to the one required in the calculation for storage tanks.

In addition to high-speed water heaters, it is possible to use other types of water heaters with high thermal and operational characteristics, small dimensions.

14.12 The minimum number of water-to-water water heaters should be taken:

two connected in parallel, each of which must be calculated for 100% of the heat load - for heating systems of buildings that do not allow interruptions in the supply of heat;

two, designed for 75% of the heat load each, - for heating systems of buildings constructed in areas with an estimated outdoor air temperature below minus 40 ° C;

one - for other heating systems;

Two, connected in parallel in each stage of heating, designed for 50% of the heat load each, - for hot water supply systems.

With a maximum heat load on hot water supply of up to 2 MW, it is allowed to provide one hot water heater in each heating stage, except for buildings that do not allow interruptions in the supply of heat to hot water supply.

When installing steam-water heaters in heating, ventilation or hot water supply systems, their number should be at least two, connected in parallel, backup water heaters can be omitted.

For technological installations that do not allow interruptions in the supply of heat, backup water heaters should be provided, designed for the heat load in accordance with the mode of operation of the technological installations of the enterprise.

14.13 Pipelines should be equipped with fittings with shut-off valves with a nominal bore of 15 mm for air release at the highest points of all pipelines and a nominal bore of at least 25 mm for draining water at the lowest points of water and condensate pipelines.

It is allowed to carry out devices for draining water not in the pit of the central heating substation, but outside the central heating substation in special chambers.

14.14 Mud collectors should be installed:

in the heating point on the supply pipelines at the input;

On the return pipeline in front of control devices and metering devices for water and heat consumption - no more than one;

in ITP - regardless of their presence in the central heating station;

in thermal units of consumers of the 3rd category - on the supply pipeline at the input.

Before mechanical water meters (vane, turbine), plate heat exchangers and other equipment, filters should be installed along the water flow (at the request of the manufacturer).

14.15 In heating points, it is not allowed to install jumpers between the supply and return pipelines of heating networks, as well as bypass pipelines in addition to pumps (except for booster pumps), elevators, control valves, mud collectors and devices for metering water and heat consumption.

Overflow regulators and steam traps must have bypass piping.

14.16 To protect against internal corrosion and scale formation of pipelines and equipment of centralized hot water supply systems connected to heating networks through water heaters, water treatment should be provided, usually carried out in the central heating station. In ITP, only magnetic and silicate water treatment is allowed.

14.17 Treatment of drinking water should not impair its sanitary and hygienic indicators. Reagents and materials used for water treatment, which have direct contact with water entering the hot water supply system, must be allowed by the Gossanepidnadzor of Russia for use in the practice of drinking water supply.

14.18 When installing storage tanks for hot water supply systems in thermal substations with vacuum deaeration, it is necessary to provide for the protection of the inner surface of the tanks from corrosion and the water in them from aeration by using sealing liquids. In the absence of vacuum deaeration, the inner surface of the tanks must be protected from corrosion through the use of protective coatings or cathodic protection. The design of the tank should include a device that prevents the ingress of sealing liquid into the hot water supply system.

14.19 For heating points, supply and exhaust ventilation should be provided, designed for air exchange, determined by heat release from pipelines and equipment. The design air temperature in the working area during the cold period of the year should be taken no higher than 28 ° C, in the warm period of the year - 5 ° C higher than the outside air temperature according to parameters A. heating point in adjacent premises. If the permissible air temperature in these rooms exceeds the permissible air temperature, measures should be taken for additional thermal insulation of the enclosing structures of adjacent rooms.

14.20 A ladder should be installed in the floor of the heating point, and if gravity water drainage is not possible, a drainage pit should be arranged with a size of at least 0.5 x 0.5 x 0.8 m. The pit is covered with a removable grate.

One drainage pump should be provided for pumping water from the catchment pit into the sewerage system, drain or associated drainage. The pump intended for pumping water from the catchment pit is not allowed to be used for flushing heat consumption systems.

14.21 In heat points, measures should be taken to prevent the excess of noise levels allowed for premises of residential and public buildings. Heating points equipped with pumps are not allowed to be placed adjacently under or above the premises of residential apartments, sleeping and playing preschool institutions, sleeping quarters of boarding schools, hotels, hostels, sanatoriums, rest houses, boarding houses, wards and operating hospitals, premises with a long stay patients, doctors' offices, auditoriums of entertainment enterprises.

14.22 The minimum clear distances from free-standing ground-based central heating stations to the outer walls of the listed premises must be at least 25 m.

In particularly cramped conditions, it is allowed to reduce the distance to 15 m, subject to the adoption of additional measures to reduce noise to an acceptable level according to sanitary standards.

14.23 According to placement on the master plan, heat points are divided into stand-alone, attached to buildings and structures and built into buildings and structures.

14.24 Heat points built into buildings should be placed in separate rooms near the outer walls of buildings.

14.25 Outputs from the heating point should be provided:

with a length of the heating point room of 12 m or less - one exit to the adjacent room, corridor or stairwell;

with a heating point room length of more than 12 m - two exits, one of which should be directly outside, the second - to an adjacent room, stairwell or corridor.

Premises of thermal points of steam consumers with a pressure of more than 0.07 MPa must have at least two exits, regardless of the dimensions of the room.

14.26 It is not required to provide openings for natural lighting of heat points. Doors and gates must be opened from the room or building of the heating point away from you.

14.27 In terms of explosion and fire hazard, the premises of heat points must comply with category D according to NPB 105.

14.28 Heat points located in the premises of production and storage buildings, as well as administrative buildings of industrial enterprises, in residential and public buildings, must be separated from other premises by partitions or fences that prevent unauthorized persons from accessing the heat point.

14.29 For the installation of equipment, the dimensions of which exceed the dimensions of the doors, in ground heating points, installation openings or gates in the walls should be provided.

At the same time, the dimensions of the installation opening and the gate should be 0.2 m larger than the overall dimensions of the largest equipment or pipeline block.

14.30 Inventory lifting and transport devices should be provided for moving equipment and fittings or integral parts of equipment blocks.

If it is impossible to use inventory devices, it is allowed to provide stationary lifting and transport devices:

With a mass of the transported cargo from 0.1 to 1.0 tons - monorails with manual hoists and crampons or manual single-girder overhead cranes;

the same, more than 1.0 to 2.0 tons - single-girder manual overhead cranes;

the same, more than 2.0 tons - single-girder electric overhead cranes.

It is allowed to provide for the possibility of using mobile lifting and transport vehicles.

14.31 For maintenance of equipment and fittings located at a height of 1.5 to 2.5 m from the floor, mobile platforms or portable devices (ladders) should be provided. If it is impossible to create passages for mobile platforms, as well as maintenance of equipment and fittings located at a height of 2.5 m or more, it is necessary to provide stationary platforms with a fence and permanent stairs. The dimensions of platforms, stairs and fences should be taken in accordance with the requirements of GOST 23120.

The distance from the level of the stationary platform to the upper floor must be at least 2 m.

14.32 In the central heating station with permanent attendants, a bathroom with a washbasin should be provided.

15 POWER SUPPLY AND CONTROL SYSTEM

15.1 Power supply of electrical receivers of heat networks should be carried out in accordance with the rules for the installation of electrical installations (PUE).

Electric receivers of heat networks in terms of reliability of power supply should be provided for:

Category II - shut-off valves for remote control, booster, mixing and circulation pumps of heat networks with a pipe diameter of less than 500 mm and heating and ventilation systems in heat points, pumps for charging and discharging storage tanks for feeding heat networks in open heat supply systems, make-up pumps in the nodes of the cut;

15.2 Control equipment for electrical installations in underground chambers should be located in rooms located above ground level.

15.3 Electric lighting should be provided in pumping stations, in heating points, pavilions, in tunnels and siphons, chambers equipped with electrical equipment, as well as on sites of overpasses and separately standing high supports at the installation sites of electric valves, regulators, instrumentation. Illumination should be taken according to current standards. Permanent emergency and evacuation lighting should be provided in the premises of permanent residence of operating and maintenance personnel. In other rooms, emergency lighting is provided by portable rechargeable lamps.

16 ADDITIONAL REQUIREMENTS FOR DESIGN OF HEAT NETWORKS IN SPECIAL NATURAL AND CLIMATIC CONDITIONS OF CONSTRUCTION

16.1 When designing heat networks and structures on them in areas with seismicity of 8 and 9 points, in undermined territories, in areas with type II subsidence soils, saline, swelling, peaty and permafrost, along with the requirements of these rules and regulations, construction requirements for buildings and structures located in these areas.

Note - With subsiding soils of type I, heat networks can be designed without taking into account the requirements of this section.

16.2 Shut-off, control and safety valves, regardless of pipe diameters and coolant parameters, should be made of steel.

16.3 The distance between sectional valves should be taken no more than 1000 m. If justified, it is allowed to increase the distance on transit pipelines up to 3000 m.

16.4 Laying of heat networks from non-metallic pipes is not allowed.

16.5 Joint laying of heat networks with gas pipelines in channels and tunnels, regardless of gas pressure, is not allowed.

It is allowed to provide for joint laying with natural gas pipelines only in intra-quarter tunnels and common trenches at a gas pressure of not more than 0.005 MPa.

Applications

APPENDIX A
(mandatory)

Appendix A. LIST OF REGULATORY DOCUMENTS REFERRED TO IN THIS DOCUMENT

GOST 9238-83 Approach dimensions of buildings and rolling stock of 1520 (1524) mm gauge railways

GOST 9720-76 Approach dimensions of buildings and rolling stock of 750 mm gauge railways

GOST 23120-78 Marching stairs, platforms and steel railings. Specifications

GOST 30494-96 Residential and public buildings. Indoor microclimate parameters

GOST 30732-2001 Steel pipes and fittings with thermal insulation made of polyurethane foam in a polyethylene sheath. Specifications

SNiP 2.02.04-88 Bases and foundations on permafrost soils

SNiP 2.04.01-85* Internal water supply and sewerage of buildings

SNiP 41-03-2003 Thermal insulation of equipment and pipelines

SanPiN 2.1.4.1074-01 Drinking water. Hygienic requirements for water quality of centralized drinking water supply systems. Quality control

NPB 105-03 Definition of categories of premises, buildings and outdoor installations for explosion and fire safety

PB 10-573-03 Rules for the design and safe operation of steam and hot water pipelines

PUE Rules for the installation of electrical installations

Rules for the technical operation of power plants and networks

RD 10-249-98 Standards for calculating the strength of stationary boilers and steam and hot water pipelines

RD 10-400-01 Norms for calculating the strength of pipelines of heat networks

RD 153-34.0-20.518-2003 Standard instruction for the protection of pipelines of heating networks from external corrosion

APPENDIX B
(mandatory)

Appendix B. DISTANCES FROM BUILDING STRUCTURES OF HEAT NETWORKS OR SHELL OF INSULATION OF PIPELINES WITH CHANNEL-LESS LAYING TO BUILDINGS, STRUCTURES AND ENGINEERING NETWORKS

Table B.1

Vertical distances

Structures and engineering networks	The smallest clear distances vertically, m

To the water supply, drain, gas pipeline, sewerage	0,2
Up to armored communication cables	0,5
Up to power and control cables up to 35 kV	0.5 (0.25 in cramped conditions) - subject to the requirements of note 5
To oil-filled cables with a voltage of St. 110 kV	1.0 (0.5 in cramped conditions) - subject to the requirements of note 5
Up to the telephone sewer block or up to the armored communication cable in pipes	0,15
To the sole of the railroad tracks of industrial enterprises	1,0
The same, railways of the general network	2,0
"tram lines	1,0
To the top of the road surface of public roads of categories I, II and III	1,0
To the bottom of a ditch or other drainage structures or to the base of an embankment of a railway subgrade (if heating networks are located under these structures)	0,5
To metro facilities (if heating networks are located above these facilities)	1,0

To the head of railroads
To the top of the carriageway	5,0
To the top of the footpaths	2,2
To parts of the contact network of the tram	0,3
Same, trolleybus	0,2
To overhead power lines with the largest sag of wires at voltage, kV:
up to 1	1,0
St. 1 to 20	3,0
35-110	4,0
150	4,5
220	5,0
330	6,0
500	6,5

Notes

1 Deepening of heat networks from the ground surface or road surface (except for motor roads of categories I, II and III) should be taken at least:

a) to the top of the ceilings of channels and tunnels - 0.5 m;

b) to the top of the ceilings of the chambers - 0.3 m;

c) up to the top of the channelless laying shell 0.7 m. In the impassable part, ceilings of chambers and ventilation shafts for tunnels and channels protruding above the ground are allowed to a height of at least 0.4 m;

D) at the input of heat networks to the building, it is allowed to take depths from the ground surface to the top of the overlap of channels or tunnels - 0.3 m and to the top of the channelless laying shell - 0.5 m;

e) at a high level of groundwater, it is allowed to provide for a decrease in the depth of channels and tunnels and the location of ceilings above the ground to a height of at least 0.4 m, if the conditions for the movement of vehicles are not violated.

2 When laying above-ground heating networks on low supports, the clear distance from the earth's surface to the bottom of the thermal insulation of pipelines must be, m, not less than:

With a group of pipes up to 1.5 m wide - 0.35;

"" "" more than 1.5 m - 0.5.

3 When laying underground, heat networks at the intersection with power, control and communication cables can be located above or below them.

4 In case of channelless laying, the clear distance from water heating networks of an open heat supply system or hot water supply networks to sewer pipes located below or above the heating networks is assumed to be at least 0.4 m.

5 The temperature of the soil at the intersection of heat networks with electric cables at a depth of laying power and control cables with a voltage of up to 35 kV should not rise by more than 10 ° C in relation to the highest average monthly summer ground temperature and by 15 ° C - to the lowest average monthly winter ground temperature at a distance of up to 2 m from the outermost cables, and the temperature of the soil at the depth of the oil-filled cable should not rise by more than 5 ° C in relation to the average monthly temperature at any time of the year at a distance of up to 3 m from the outermost cables.

6 Deepening of heat networks in places of underground crossing of railways of the general network in heaving soils is determined by calculation from the conditions under which the influence of heat releases on the uniformity of frost heaving of the soil is excluded. If it is impossible to ensure the specified temperature regime due to the deepening of heating networks, ventilation of tunnels (channels, cases), replacement of heaving soil at the intersection or above-ground laying of heating networks is provided.

7 Distances to a telephone duct or to an armored communication cable in pipes should be specified according to special standards.

8 In places of underground intersections of heat networks with communication cables, telephone sewerage units, power and control cables with voltage up to 35 kV, it is allowed, with appropriate justification, to reduce the vertical distance in the light when installing reinforced thermal insulation and observing the requirements of paragraphs 5, 6, 7 of these notes.

Table B.2

Horizontal distances from underground water heat networks of open heat supply systems and hot water supply networks to sources of possible pollution

Source of pollution	The smallest clear distances horizontally, m
1. Structures and pipelines of household and industrial sewerage:
when laying heating networks in channels and tunnels	1,0
for channelless laying of heat networks D_y<= 200 мм	1,5
The same, D_y > 200 mm	3,0
2. Cemeteries, landfills, cattle burial grounds, irrigation fields:
in the absence of groundwater	10,0
	50,0
3. Cesspools and garbage pits:
in the absence of groundwater	7,0
in the presence of groundwater and in filtering soils with the movement of groundwater towards heating networks	20,0

Note - When sewerage networks are located below heating networks with parallel laying, horizontal distances should be taken at least the difference in the elevations of the networks, above the heating networks - the distances indicated in the table should increase by the difference in the laying depth.

Table B.3

Horizontal distances from the building structures of heat networks or the pipeline insulation shell in case of channelless laying to buildings, structures and engineering networks

Buildings, structures and engineering networks	The smallest clear distances, m
Underground laying of heating networks
To the foundations of buildings and structures:
a) when laying in channels and tunnels and non-sagging soils (from the outer wall of the tunnel channel) with a pipe diameter, mm:
D_y< 500	2,0
D_y = 500-800	5,0
D_y = 900 and more	8,0

D_y< 500	5,0
D_y >= 500	8,0
b) for channelless laying in non-sagging soils (from the shell of the channelless laying) with a pipe diameter, mm:
D_y< 500	5,0
D_y >= 500	7,0
The same, in subsiding soils of type I with:
D_y<= 100	5,0
D_y > 100 to D_y< 500	7,0
D_y >= 500	8,0
To the axis of the nearest track of the 1520 mm gauge railway	4.0 (but not less than the depth of the heating network trench to the bottom of the embankment)
The same, 750 mm track	2,8
To the nearest railroad subgrade structure	3.0 (but not less than the depth of the heating network trench to the base of the outermost structure)
To the axis of the nearest track of the electrified railway	10,75
	2,8
To the side stone of the street of the road (edge of the carriageway, reinforced roadside)	1,5
To the outer edge of the ditch or the bottom of the road embankment	1,0
To the foundations of fences and pipeline supports	1,5
Up to outdoor lighting masts and poles and communication networks	1,0
To the foundations of the supports of the overpass bridges	2,0
To the foundations of the poles of the contact network of railways	3,0
The same trams and trolleybuses	1,0
Up to power and control cables up to 35 kV and oil-filled cables (up to 220 kV)	2.0 (see note 1)
To the foundations of overhead transmission line supports at voltage, kV (when approaching and crossing):
up to 1	1,0
St. 1 to 35	2,0
St. 35	3,0
To the telephone sewer block, armored communication cable in pipes and to radio transmission cables	1,0
Before the water pipes	1,5
The same, in subsiding soils of type I	2,5
Before drains and rainwater	1,0
To industrial and household sewerage (with a closed heat supply system)	1,0
Up to gas pipelines with a pressure of up to 0.6 MPa when laying heating networks in channels, tunnels, as well as for channelless laying with associated drainage	2,0
The same, more than 0.6 to 1.2 MPa	4,0
To gas pipelines with pressure up to 0.3 MPa with channelless laying of heat networks without associated drainage	1,0
The same, more than 0.3 to 0.6 MPa	1,5
The same, more than 0.6 to 1.2 MPa	2,0
Up to the tree trunk	2.01 (see note 10)
Down to the bushes	1.0 (see note 10)
To canals and tunnels for various purposes (including to the edge of canals of irrigation networks - ditches)	2,0
Up to subway structures when lining with external gluing insulation	5.0 (but not less than the depth of the heat network trenches to the base of the structure)
The same, without pasting waterproofing	8.0 (but not less than the depth of the trenches of the heat network to the base of the structure)
To the fencing of surface subway lines	5
To the tanks of automobile filling stations (gas stations):
a) with channelless laying	10,0
b) with channel laying (subject to the installation of ventilation shafts on the channel of heating networks)	15,0
Above-ground laying of heating networks
To the nearest railroad subgrade structure	3
To the axis of the railway track from intermediate supports (when crossing railways)	Dimensions "C", "Sp", "Su" according to GOST 9238 and GOST 9720
To the axis of the nearest tram track	2,8
To the side stone or to the outer edge of the road ditch	0,5
To the overhead power line with the largest deviation of wires at voltage, kV:	(See note 8)
up to 1	1
St. 1 to 20	3
35-110	4
150	4,5
220	5
330	6
500	6,5
Down to the tree trunk	2,0
To residential and public buildings for water heating networks, steam pipelines with pressure Р_у<= 0,63 МПа, конденсатных тепловых сетей при диаметрах труб, мм:
D_y from 500 to 1400	25 (see note 9)
D_y from 200 to 500	20 (see note 9)
D_y< 200	10 (see note 9)
To hot water networks	5
The same, to steam heating networks:
Р_у from 1.0 to 2.5 MPa	30
St. 2.5 to 6.3 MPa	40

Notes

1 It is allowed to reduce the distance given in Table B.3, subject to the condition that in the entire area of approach of heat networks to cables, the temperature of the soil (accepted according to climatic data) at the place where the cables pass at any time of the year will not increase compared to the average monthly temperature by more than 10 °С for power and control cables with voltage up to 10 kV and 5 °С for power control cables with voltage 20 - 35 kV and oil-filled cables up to 220 kV.

2 When laying heat and other engineering networks in common trenches (with their simultaneous construction), it is allowed to reduce the distance from heat networks to water supply and sewerage systems to 0.8 m when all networks are located at the same level or with a difference in laying marks of not more than 0.4 m.

3 For heat networks laid below the foundation of the foundations of supports, buildings, structures, the difference in elevations should be additionally taken into account, taking into account the natural slope of the soil, or measures should be taken to strengthen the foundations.

4 When laying parallel underground heat and other engineering networks at different depths, the distances given in Table B.3 should increase and be taken not less than the difference in the laying of networks. In cramped laying conditions and the impossibility of increasing the distance, measures should be taken to protect engineering networks from collapse during the repair and construction of heating networks.

5 When parallel laying heat and other engineering networks, it is allowed to reduce the distances given in Table B.3 to structures on networks (wells, chambers, niches, etc.) to a value of at least 0.5 m, providing for measures to ensure the safety of structures when production of construction and installation works.

6 Distances to special communication cables must be specified in accordance with the relevant standards.

7 The distance from the ground pavilions of heating networks for the placement of shut-off and control valves (in the absence of pumps in them) to residential buildings is taken at least 15 m. In particularly cramped conditions, it can be reduced to 10 m.

8 When parallel laying of above-ground heat networks with an overhead power line with a voltage of more than 1 to 500 kV outside settlements, the horizontal distance from the outermost wire should be taken not less than the height of the support.

9 When laying temporary (up to 1 year of operation) water heating networks (bypasses) above ground, the distance to residential and public buildings can be reduced while ensuring the safety of residents (100% control of welds, testing of pipelines by 1.5 of the maximum working pressure, but not less than 1.0 MPa, application

to the channel wallto the surface of the heat-insulating structure of the adjacent pipelinebefore channel closureto the bottom of the channel 25-80 70 100 50 100 100-250 80 140 50 150 300-350 100 160 70 150 400 100 200 70 180 500-700 110 200 100 180 800 120 250 100 200 900-1400 120 250 100 300

Note - When reconstructing heat networks using existing channels, deviations from the dimensions indicated in this table are allowed.

Table B.2

Tunnels, above-ground laying and substations

In millimeters

Conditional passage of pipelines	Distance from the surface of the heat-insulating structure of pipelines in the light, not less than
	to the tunnel wall	before closing the tunnel	to the bottom of the tunnel	to the surface of the heat-insulating structure of the adjacent pipeline in tunnels, with above-ground laying and in heating points
	to the tunnel wall	before closing the tunnel	to the bottom of the tunnel	vertically	horizontally
25-80	150	100	150	100	100
100-250	170	100	200	140	140
300-350	200	120	200	160	160
400	200	120	200	160	200
500-700	200	120	200	200	200
800	250	150	250	200	250
900	250	150
up to 500	600
from 600 to 900	700
from 1000 and more	1000
From the wall to the flange of the stuffing box compensator housing (from the branch pipe side) with pipe diameters, mm:
up to 500	600 (along the pipe axis)
600 and more	800 (along the pipe axis)
From the floor or ceiling to the valve flange or to the axis of the gland packing bolts	400
The same, up to the surface of the heat-insulating structure of pipe branches	300
Extended valve stem (or handwheel) to wall or slab	200
For pipes with a diameter of 600 mm or more between the walls of adjacent pipes on the side of the gland compensator	500
From wall or valve flange to water or air outlets	100
From the gate valve flange on the branch to the surface of the heat-insulating structures of the main pipes	100
Between heat-insulating structures of adjacent bellows expansion joints with expansion joint diameters, mm:
up to 500	100
600 and more	150

C.2 The minimum distances from the edge of the movable supports to the edge of the support structures (traverses, brackets, support pads) should ensure the maximum possible displacement of the support in the lateral direction with a margin of at least 50 mm. In addition, the minimum distances from the edge of the traverse or bracket to the axis of the pipe, excluding displacement, must be at least 0.5 D_y.

B.3 The maximum clear distances from the heat-insulating structures of the bellows expansion joints to the walls, ceilings and bottom of the tunnels should be taken:

at D_y<= 500 - 100 мм;

with D_y = 600 and more - 150 mm.

If it is impossible to comply with the specified distances, the expansion joints should be installed in a run-up with an offset in plan of at least 100 mm relative to each other.

C.4 The distance from the surface of the heat-insulating structure of the pipeline to building structures or to the surface of the heat-insulating structure of other pipelines after the thermal movement of the pipelines must be at least 30 mm in the light.

B.5 The clear passage width in tunnels should be taken equal to the diameter of the larger pipe plus 100 mm, but not less than 700 mm.

B.6 The supply pipeline of two-pipe water heating networks, when it is laid in the same row with the return pipeline, should be located to the right along the course of the coolant from the heat source.

B.7 It is allowed to attach pipes of smaller diameters to pipelines with a coolant temperature not exceeding 300 °C during above-ground laying.

B.8 Gland compensators on the supply and return pipelines of water heating networks in the chambers can be installed with an offset of 150 - 200 mm relative to each other in plan, and flange valves D_y<= 150 мм и сильфонные компенсаторы - в разбежку с расстоянием (по оси) в плане между ними не менее 100 мм.

B.9 In thermal points, the width of the passages in the clear, m, should be taken, not less than:

between pumps with electric motors up to 1000 V - 1.0;

the same, 1000 V and above - 1.2;

between pumps and wall - 1.0;

between pumps and switchboard or instrumentation panel - 2.0;

between the protruding parts of the equipment or between these parts and the wall - 0.8.

Pumps with electric motors with voltage up to 1000 V and a discharge pipe diameter of not more than 100 mm are allowed to be installed:

At the wall without a passage; at the same time, the distance from the protruding parts of pumps and electric motors to the wall must be at least 0.3 m in the light;

two pumps on the same foundation without a passage between them; at the same time, the distance between the protruding parts of pumps with electric motors must be at least 0.3 m in the clear.

B.10 The central heating station should provide for mounting sites, the dimensions of which are determined by the dimensions of the largest piece of equipment (except for a tank with a capacity of more than 3 m3) or a block of equipment and pipelines supplied for installation in assembled form, with a passage around them of at least 0.7 m.

The website "Zakonbase" presents "HEAT NETWORKS. BUILDING NORMS AND RULES. SNiP 41-02-2003" (approved by the Decree of the Gosstroy of the Russian Federation of 06.24.2003 N 110) in the latest edition. It is easy to comply with all legal requirements if you familiarize yourself with the relevant sections, chapters and articles of this document for 2014. To search for the necessary legislative acts on a topic of interest, you should use convenient navigation or advanced search.

On the website "Zakonbase" you will find "HEAT NETWORKS. BUILDING NORMS AND RULES. SNiP 41-02-2003" (approved by the Decree of the Gosstroy of the Russian Federation of 06.24.2003 N 110) in a fresh and complete version, in which all changes and amendments have been made. This guarantees the relevance and reliability of the information.

STATE COMMITTEE OF THE RUSSIAN FEDERATION
FOR CONSTRUCTION AND HOUSING AND UTILITY COMPLEX
(GOSSTROY OF RUSSIA)

The system of regulatory documents in construction

BUILDING NORMS AND RULES OF THE RUSSIAN FEDERATION

HEATING NETWORK

THERMAL NETWORKS

SNiP 41-02-2003

UDC 69+697.34 (083.74)
Introduction date 2003-09-01

FOREWORD

1 DEVELOPED BY VNIPIenergoprom Association JSC, Perm State Technical University, Teploproekt JSC with the participation of the Association of Developers and Manufacturers of Anticorrosion Protection for the Fuel and Energy Complex, the Association of Manufacturers and Consumers of Pipelines with Industrial Polymer Insulation, ORGRES Firm JSC, ORGRES JSC All-Russian Thermal Engineering Institute, SevZapVNIPIenergoprom, CJSC TVEL Corporation, Mosgorexpertiza, OJSC Mosproekt, State Unitary Enterprise Mosinzhproekt, CJSC NTP Truboprovod, CJSC Roskommunenergo, OJSC Lengazteplostroy, Irkutsk State Technical University, CJSC " Insulation Plant", Tyumen Academy of Civil Engineering and Architecture

INTRODUCED by the Department of technical regulation, standardization and certification in construction and housing and communal services of the Gosstroy of Russia

2 ADOPTED AND PUT INTO EFFECT on September 1, 2003 by Resolution of the Gosstroy of Russia No. 110 of June 24, 2003

3 INSTEAD OF SNiP 2.04.07-86*

INTRODUCTION

These building codes and regulations establish a set of mandatory regulatory requirements for the design of heat networks, structures on heat networks in conjunction with all elements of district heating systems in terms of their interaction in a single technological process of production, distribution, transportation and consumption of heat energy, rational use of fuel and energy resources.
Requirements for safety, reliability, and survivability of heat supply systems have been established.
When developing the SNiP, normative materials from leading Russian and foreign companies were used, and 17 years of experience in applying the current standards by design and operating organizations in Russia were taken into account.
In building codes and regulations for the first time:
norms of environmental and operational safety, readiness (quality) of heat supply were introduced; extended application of the criterion of the probability of no-failure operation;
the principles and requirements for ensuring survivability in off-design (extreme) conditions are formulated, the signs of district heating systems are clarified;
standards for the application of reliability criteria in the design of heat networks have been introduced;
Criteria for the selection of heat-insulating structures, taking into account fire safety, are given.
The following took part in the development of SNiP: Ph.D. tech. Sciences Ya.A. Kovylyansky, A.I. Korotkov, Ph.D. tech. Sciences G.Kh. Umerkin, A.A. Sheremetova, L.I. Zhukovskaya, L.V. Makarova, V.I. Zhurina, Ph.D. tech. Sciences B.M. Krasovsky, Ph.D. tech. Sciences A.V. Grishkova, Ph.D. tech. Sciences T.N. Romanova, Ph.D. tech. Sciences B.M. Shoikhet, L.V. Stavritskaya, Dr. Sc. Sciences A.L. Akolzin, Ph.D. tech. Sciences I.L. Meisel, E.M. Shmyrev, L.P. Kanina, L.D. Satanov, R.M. Sokolov, Dr. tech. Sciences Yu.V. Balaban-Irmenin, A.I. Kravtsov, Sh.N. Abaiburov, V.N. Simonov, Ph.D. tech. Sciences V.I. Livchak, A.V. Fisher, Yu.U. Yunusov, N.G. Shevchenko, Ph.D. tech. Sciences V.Ya. Magalif, A.A. Khandrikov, L.E. Lyubetsky, Ph.D. tech. Sciences R.L. Ermakov, B.C. Votintsev, T.F. Mironova, Dr. tech. Sciences A.F. Shapoval, V.A. Glukharev, V.P. Bovbel, L.S. Vasiliev.

1 AREA OF USE

These rules and regulations apply to heat networks (with all associated structures) from the outlet shut-off valves (excluding them) of the heat source collectors or from the outer walls of the heat source to the outlet shut-off valves (including them) of heat points (inlet nodes) of buildings and structures that transport hot water with temperature up to 200 °C and pressure up to 2.5 MPa inclusive, steam with temperature up to 440 °C and pressure up to 6.3 MPa inclusive, steam condensate.
The composition of heat networks includes buildings and structures of heat networks: pumping stations, heat points, pavilions, chambers, drainage devices, etc.
These standards consider district heating systems (hereinafter referred to as DH) in terms of their interaction in a single technological process of production, distribution, transportation and consumption of heat.
These norms and rules should be observed when designing new and reconstructing, modernizing and technically re-equipping existing heat networks (including facilities on heat networks).

3 TERMS AND DEFINITIONS

The following terms and definitions are used in these standards.
District heating system - a system consisting of one or more heat sources, heat networks (regardless of the diameter, number and length of external heat pipelines) and heat consumers.
The probability of failure-free operation of the system [R] is the ability of the system to prevent failures that lead to a temperature drop in heated rooms of residential and public buildings below +12 °C, in industrial buildings below +8 °C, more than the number of times established by the standards.
Availability (quality) coefficient of the system - the probability of a working state of the system at an arbitrary moment in time to maintain the calculated internal temperature in the heated premises, except for periods of temperature decrease allowed by the standards.
System survivability [L] - the ability of the system to maintain its performance in emergency (extreme) conditions, as well as after long (more than 54 hours) shutdowns.
Service life of heat networks - a period of time in calendar years from the date of commissioning, after which an expert examination of the technical condition of the pipeline should be carried out in order to determine the admissibility, parameters and conditions for further operation of the pipeline or the need for its dismantling.

4 CLASSIFICATION

4.1 Heat networks are subdivided into main, distribution, quarterly and branches from main and distribution heat networks to individual buildings and structures. The separation of heat networks is established by the project or the operating organization.
4.2 Consumers of heat according to the reliability of heat supply are divided into three categories:
The first category is consumers who do not allow interruptions in the supply of the calculated amount of heat and the decrease in air temperature in the premises below those stipulated by GOST 30494.
For example, hospitals, maternity hospitals, day care centers for children, art galleries, chemical and special industries, mines, etc.
The second category is consumers who allow a decrease in temperature in heated rooms for the period of liquidation of the accident, but not more than 54 hours:
residential and public buildings up to 12 °С;
industrial buildings up to 8 °C.
The third category is other consumers.

5 GENERAL

5.1 Decisions on the long-term development of heat supply systems for settlements, industrial centers, groups of industrial enterprises, districts and other administrative-territorial entities, as well as individual district heating systems should be developed in heat supply schemes. When developing heat supply schemes, the calculated heat loads are determined by:
a) for the existing development of settlements and operating industrial enterprises - for projects with clarification on actual heat loads;
b) for industrial enterprises planned for construction - according to the consolidated norms for the development of the main (core) production or projects of similar production;
c) for residential areas planned for development - according to aggregated indicators of the density of placement of thermal loads or according to the specific thermal characteristics of buildings and structures in accordance with the master plans for the development of areas of the settlement.
5.2 Estimated heat loads in the design of heat networks are determined according to the data of specific new construction projects, and the existing one - according to actual heat loads. In the absence of data, it is allowed to follow the instructions in 5.1. Average loads on hot water supply of individual buildings are allowed to be determined according to SNiP 2.04.01.
5.3 Estimated heat losses in heat networks should be determined as the sum of heat losses through the insulated surfaces of pipelines and the average annual losses of the heat carrier.
5.4 In case of accidents (failures) at the heat source, its output manifolds during the entire repair and recovery period must be provided with:
supply of 100% of the required heat to consumers of the first category (unless other modes are provided for by the contract);
supply of heat for heating and ventilation to housing and communal and industrial consumers of the second and third categories in the amounts indicated in table 1;

Table 1

Name of indicator Estimated outdoor air temperature for designing heating to, ° С

Permissible decrease in heat supply, %, up to 78 84 87 89 91
Note - The table corresponds to the outdoor temperature of the coldest five-day period with a security of 0.92.

emergency mode of steam and process hot water consumption set by the consumer;
the emergency thermal mode of operation of non-switchable ventilation systems specified by the consumer;
average daily heat consumption for the heating period for hot water supply (if it is impossible to turn it off).
5.5 When several heat sources work together for a single district (city) heat network, mutual redundancy of heat sources should be provided, providing an emergency mode according to 5.4.

6 HEAT SUPPLY AND HEAT NETWORKS

6.1 The choice of a variant of the heat supply scheme of the facility: centralized heat supply systems from boiler houses, large and small thermal and nuclear power plants (CHP, TPP, NPP) or from sources of decentralized heat supply (DCH) - autonomous, roof boilers, from apartment heat generators is made by technical and economic comparison options.
The heat supply scheme adopted for development in the project should provide:
normative level of heat and energy saving;
normative level of reliability, determined by three criteria: the probability of failure-free operation, availability (quality) of heat supply and survivability;
environmental requirements;
operational safety.
6.2 The operation of heat networks and DH as a whole should not lead to:
a) to an unacceptable concentration in the process of operation of toxic and harmful substances for the population, maintenance personnel and the environment in tunnels, channels, chambers, rooms and other structures, in the atmosphere, taking into account the ability of the atmosphere to self-purify in a particular residential quarter, microdistrict, locality, etc.;
b) to a persistent violation of the natural (natural) thermal regime of the vegetation cover (grass, shrubs, trees), under which heat pipelines are laid.
6.3 Heating networks, regardless of the method of laying and the heat supply system, should not pass through the territory of cemeteries, landfills, animal burial grounds, radioactive waste burial sites, irrigation fields, filtration fields and other areas that pose a danger of chemical, biological and radioactive contamination of the coolant.
Technological devices of industrial enterprises, from which harmful substances can enter the heating networks, must be connected to the heating networks through a water heater with an additional intermediate circulation circuit between such an apparatus and the water heater, while ensuring that the pressure in the intermediate circuit is less than in the heating network. In this case, it is necessary to provide for the installation of sampling points to control harmful impurities.
Hot water supply systems for consumers to steam networks should be connected through steam-water water heaters.
6.4 Safe operation of heat networks should be ensured by developing measures in projects that exclude:
contact of people directly with hot water or hot surfaces of pipelines (and equipment) at coolant temperatures above 75 °C;
the flow of coolant into heat supply systems with temperatures above those determined by safety standards;
reduction in case of DH failures of air temperature in residential and industrial premises of consumers of the second and third categories below the permissible values (4.2);
draining network water in places not provided for by the project.
6.5 The temperature on the surface of the heat-insulating structure of heat pipelines, fittings and equipment should not exceed:
when laying heat pipelines in the basements of buildings, technical undergrounds, tunnels and passage channels 45 ° C;
for above-ground laying, in chambers and other places accessible for maintenance, 60 °С.
6.6 The heat supply system (open, closed, including with separate hot water supply networks, mixed) is selected on the basis of a feasibility study of various systems submitted by the design organization, taking into account local environmental, economic conditions and the consequences of making a particular decision.
6.7 Direct water intake of network water from consumers in closed heat supply systems is not allowed.
6.8 In open heat supply systems, the connection of a part of consumers of hot water supply through water-to-water heat exchangers at heat points of subscribers (through a closed system) is allowed as temporary, provided that the quality of network water is ensured (maintained) in accordance with the requirements of current regulatory documents.
6.9 With nuclear heat sources, as a rule, open heat supply systems should be designed to exclude the possibility of unacceptable concentrations of radionuclides in network water, pipelines, DH equipment and in consumer heat receivers.
6.10 The composition of the SCT should include:
emergency recovery services (ABC), the number of personnel and technical equipment of which must ensure the complete restoration of heat supply in case of failures in heating networks within the time limits indicated in table 2;
own repair and maintenance bases (REB) - for areas of heating networks with an operation volume of 1000 conventional units or more. The number of personnel and technical equipment of electronic warfare are determined taking into account the composition of the equipment, the applied designs of heat pipelines, thermal insulation, etc.;
mechanical workshops - for sections (workshops) of heating networks with an operating volume of less than 1000 conventional units;
unified repair and maintenance bases - for heating networks that are part of the divisions of thermal power plants, district boiler houses or industrial enterprises.

Heating network schemes

6.11 Water heating networks should be designed, as a rule, with two pipes, simultaneously supplying heat for heating, ventilation, hot water supply and technological needs.
Multi-pipe and single-pipe heating networks are allowed to be used during a feasibility study.
Heat networks transporting network water in one direction in open heat supply systems, with above-ground laying, it is allowed to design in a single-pipe design with a transit length of up to 5 km. With a greater length and the absence of reserve feeding of the DH from other sources of heat, heat networks should be carried out in two (or more) parallel heat pipelines.
Independent heat networks for connecting technological heat consumers should be provided if the quality and parameters of the heat carrier differ from those accepted in heat networks.
6.12 The scheme and configuration of heat networks should ensure heat supply at the level of specified reliability indicators by:
application of the most advanced designs and technical solutions;
joint work of heat sources;
laying of reserve heat pipelines;
devices of jumpers between thermal networks of adjacent thermal regions.
6.13 Heating networks can be ring and dead-end, redundant and non-redundant.
The number and location of backup pipeline connections between adjacent heat pipelines should be determined by the criterion of the probability of failure-free operation.
6.14 Consumer heating and ventilation systems must be connected to two-pipe water heating networks directly according to a dependent connection scheme.
According to an independent scheme, which provides for the installation of water heaters in heat points, it is allowed to connect other consumers when justifying the heating and ventilation system of buildings 12 floors and above, if independent connection is due to the hydraulic mode of the system.
6.15 The quality of source water for open and closed heat supply systems must meet the requirements of SanPiN 2.1.4.1074 and the rules for the technical operation of power plants and networks of the Ministry of Energy of Russia.
For closed heat supply systems in the presence of thermal deaeration, it is allowed to use industrial water.
6.16 Estimated hourly water consumption to determine the productivity of water treatment and the corresponding equipment for feeding the heat supply system should be taken:
in closed heat supply systems - 0.75% of the actual volume of water in the pipelines of heat networks and the heating and ventilation systems of buildings connected to them. At the same time, for sections of heating networks with a length of more than 5 km from heat sources without heat distribution, the estimated water flow should be taken equal to 0.5% of the volume of water in these pipelines;
in open heat supply systems - equal to the calculated average water consumption for hot water supply with a coefficient of 1.2 plus 0.75% of the actual volume of water in the pipelines of heat networks and the heating, ventilation and hot water supply systems of buildings connected to them. At the same time, for sections of heating networks with a length of more than 5 km from heat sources without heat distribution, the estimated water flow should be taken equal to 0.5% of the volume of water in these pipelines;
for individual heating networks of hot water supply in the presence of storage tanks - equal to the calculated average water consumption for hot water supply with a coefficient of 1.2; in the absence of tanks - according to the maximum water consumption for hot water supply plus (in both cases) 0.75% of the actual volume of water in the pipelines of the networks and the hot water supply systems of buildings connected to them.
6.17 For open and closed heat supply systems, an additional emergency make-up of chemically untreated and non-deaerated water should be provided, the flow rate of which is taken in the amount of 2% of the volume of water in the pipelines of heat networks and the heating and ventilation systems connected to them and in hot water supply systems for open heat supply systems. If there are several separate heat networks extending from the heat source collector, emergency make-up may be determined only for one heat network with the largest volume. For open heat supply systems, emergency make-up should be provided only from domestic and drinking water supply systems.
6.18 The volume of water in heat supply systems, in the absence of data on actual volumes of water, is allowed to be taken equal to 65 m3 per 1 MW of the calculated heat load with a closed heat supply system, 70 m3 per 1 MW - with an open system and 30 m3 per 1 MW of average load - with separate networks hot water supply.
6.19 Placement of hot water storage tanks is possible both at the heat source and in areas of heat consumption. At the same time, storage tanks with a capacity of at least 25% of the total estimated capacity of the tanks should be provided at the heat source. The inner surface of the tanks must be protected from corrosion, and the water in them must be protected from aeration, while continuous renewal of the water in the tanks must be provided.
6.20 For open heat supply systems, as well as for separate heat networks for hot water supply, storage tanks of chemically treated and deaerated make-up water, with a design capacity equal to ten times the average hourly water consumption for hot water supply, should be provided.
6.21 In closed heat supply systems on heat sources with a capacity of 100 MW or more, tanks for the supply of chemically treated and deaerated make-up water with a capacity of 3% of the volume of water in the heat supply system should be provided, while water renewal in the tanks should be ensured.
The number of tanks, regardless of the heat supply system, is taken at least two by 50% of the working volume.
6.22 In DH with heat pipelines of any length from the heat source to heat consumption areas, it is allowed to use heat pipelines as storage tanks.
6.23 When a group of storage tanks is located outside the territory of heat sources, it must be fenced with a common shaft with a height of at least 0.5 m.
6.24 It is not allowed to install hot water storage tanks in residential areas. The distance from the hot water storage tanks to the border of residential areas must be at least 30 m. At the same time, on soils of the 1st type of subsidence, the distance, in addition, must be at least 1.5 thickness of the subsiding soil layer.
When placing storage tanks outside the territory of heat sources, their fencing should be provided at least 2.5 m high to prevent unauthorized persons from accessing the tanks.
6.25 Hot water storage tanks for consumers should be provided in the hot water supply systems of industrial enterprises to equalize the shift schedule of water consumption by facilities that have concentrated short-term water consumption for hot water supply.
For objects of industrial enterprises that have a ratio of the average heat load for hot water supply to the maximum heat load for heating is less than 0.2, storage tanks are not installed.
6.26 To reduce the loss of network water and, accordingly, heat during planned or forced emptying of heat pipes, it is allowed to install special storage tanks in heat networks, the capacity of which is determined by the volume of heat pipes between two sectional valves.

Reliability

6.27 The ability of the designed and existing heat sources, heat networks and the DH system as a whole to provide the required modes, parameters and quality of heat supply (heating, ventilation, hot water supply, as well as the technological needs of enterprises in steam and hot water) for a given time should be determined by three indicators (criteria): the probability of failure-free operation [P], availability factor [Kg], survivability [Zh].
Calculation of indicators of the system taking into account reliability should be made for each consumer.
6.28 The minimum acceptable indicators of the probability of failure-free operation should be taken for:
heat source Rit = 0.97;
heating networks Rts = 0.9;
heat consumer Рpt = 0.99;
MCT as a whole Рstst = 0.9 0.97 0.99 = 0.86.
The customer has the right to set higher rates in the design specification.
6.29 To ensure the reliability of heat networks, the following should be determined:
the maximum allowable length of non-reserved sections of heat pipelines (dead-end, radial, transit) to each consumer or heat point;
locations of backup pipeline connections between radial heat pipelines;
sufficiency of diameters chosen during the design of new or reconstructed existing heat pipelines to ensure backup heat supply to consumers in case of failures;
the need to replace the structures of heating networks and heat pipelines in specific areas with more reliable ones, as well as the validity of the transition to above-ground or tunnel laying;
the sequence of repairs and replacements of heat pipelines that have partially or completely lost their resource;
the need to carry out work on additional insulation of buildings.
6.30 The readiness of the system for proper operation should be determined by the number of hours of waiting for readiness: a heat source, heating networks, heat consumers, as well as the number of hours of off-design outdoor temperatures in a given area.
6.31 The minimum allowable indicator of readiness of the central heating system for proper operation Kg is assumed to be 0.97.
6.32 To calculate the readiness indicator, it is necessary to determine (take into account):
readiness of DH for the heating season;
the sufficiency of the installed thermal capacity of the heat source to ensure the proper functioning of the DH in case of off-design cooling;
the ability of heat networks to ensure the proper functioning of the DH during off-design cooling;
organizational and technical measures necessary to ensure the proper functioning of the central heating system at the level of a given readiness;
the maximum allowable number of hours of readiness for the heat source;
outdoor air temperature at which the set indoor air temperature is achieved.

Reservation

6.33 The following redundancy methods should be considered:
the use of rational thermal schemes on heat sources that provide a given level of readiness of power equipment;
installation of the necessary backup equipment at the heat source;
organization of joint work of several heat sources on a single system of heat transportation;
reservation of heat networks of adjacent areas;
arrangement of backup pumping and pipeline connections;
installation of storage tanks.
When laying underground heating networks in impassable channels and channelless laying, the value of heat supply (%) to ensure the internal air temperature in heated rooms is not lower than 12 ° C during the repair and recovery period after a failure should be taken from Table 2.

table 2

Diameter of pipes of heating networks, mm Heat supply restoration time, h Design outdoor air temperature for heating design tо, °C

minus 10 minus 20 minus 30 minus 40 minus 50

Permissible reduction in heat supply, %, up to
300 15 32 50 60 59 64
400 18 41 56 65 63 68
500 22 49 63 70 69 73
600 26 52 68 75 73 77
700 29 59 70 76 75 78
800-1000 40 66 75 80 79 82
1200-1400 Up to 54 71 79 83 82 85

6.34 Above-ground laying sections up to 5 km long may not be reserved, except for pipelines with a diameter of more than 1200 mm in areas with design air temperatures for heating design below minus 40 °С.
It is allowed not to provide for the reservation of heat supply through heating networks laid in tunnels and passage channels.
6.35 For consumers of the first category, the installation of local backup heat sources (stationary or mobile) should be provided. It is allowed to provide for redundancy, which ensures 100% heat supply from other heating networks in case of failures.
6.36 To reserve the heat supply of industrial enterprises, it is allowed to provide local sources of heat.

Vitality

6.37 The minimum heat supply through heat pipelines located in unheated premises and outside, in entrances, stairwells, attics, etc., should be sufficient to maintain the water temperature during the entire repair and recovery period after a failure of at least 3 °C.
6.38 The projects should develop measures to ensure the survivability of elements of heat supply systems located in areas of possible effects of negative temperatures, including:
organization of local circulation of network water in heating networks before and after the CHP;
descent of network water from heat use systems at consumers, distribution heat networks, transit and main heat pipelines;
heating and filling of heating networks and systems of heat use of consumers during and after the completion of repair and restoration work;
checking the strength of heating network elements for the adequacy of the safety margin of equipment and compensating devices;
ensuring the necessary weight of channelless laid heat pipelines in case of possible flooding;
temporary use, if possible, of mobile heat sources.

Collection and return of condensate

6.39 Systems for collecting and returning condensate to the heat source should be closed, while the overpressure in the condensate collection tanks should be at least 0.005 MPa.
Open systems for the collection and return of condensate may be provided if the amount of condensate returned is less than 10 t/h and the distance to the heat source is up to 0.5 km.
6.40 Condensate return from steam traps through the general network is allowed to be used if the difference in steam pressure in front of the steam traps is not more than 0.3 MPa.
When condensate is returned by pumps, the number of pumps supplying condensate to the general network is not limited.
Parallel operation of pumps and steam traps that discharge condensate from steam consumers to a common condensate network is not allowed.
6.41 Pressure condensate pipelines should be calculated according to the maximum hourly flow rate of condensate, based on the operating conditions of pipelines with a full cross section in all modes of condensate return and their protection from emptying during interruptions in the supply of condensate. The pressure in the network of condensate pipelines in all modes must be assumed to be excessive.
Condensate pipelines from steam traps to condensate collection tanks should be designed taking into account the formation of a steam-water mixture.
6.42 Specific pressure losses due to friction in the condensate pipelines after the pumps should be taken as not more than 100 Pa/m with an equivalent roughness of the internal surface of the condensate pipelines of 0.001 m.
6.43 The capacity of condensate collection tanks installed in heating networks at consumer heating points should be taken at least 10-minute maximum condensate flow. The number of tanks for year-round operation should be taken at least two, with a capacity of 50% each. For seasonal operation and less than 3 months a year, as well as with a maximum condensate flow rate of up to 5 t/h, it is allowed to install one tank.
When monitoring the quality of condensate, the number of tanks should, as a rule, be at least three with a capacity of each, providing time for the analysis of condensate for all necessary indicators, but not less than a 30-minute maximum condensate inflow.
6.44 The supply (capacity) of pumps for pumping condensate should be determined by the maximum hourly flow rate of condensate.
The pump head must be determined by the value of the pressure loss in the condensate pipeline, taking into account the height of the condensate rise from the pump room to the collection tank and the excess pressure in the collection tanks.
The pressure of pumps supplying condensate to the general network must be determined taking into account the conditions of their parallel operation in all modes of condensate return.
The number of pumps in each pumping station should be at least two, one of which is standby.
6.45 Permanent and emergency discharges of condensate into rainwater or household sewage systems are allowed after it has cooled to a temperature of 40 °C. When discharged into the industrial sewerage system with permanent drains, the condensate may not be cooled.
6.46 The condensate returned from consumers to the heat source must comply with the requirements of the rules for the technical operation of power plants and networks of the Ministry of Energy of Russia.
The return condensate temperature for open and closed systems is not standardized.
6.47 Condensate collection and return systems should provide for the use of its heat for the company's own needs.

7 HEAT MEDIA AND THEIR PARAMETERS

7.1 In district heating systems for heating, ventilation and hot water supply of residential, public and industrial buildings, as a rule, water should be taken as a heat carrier.
The possibility of using water as a heat carrier for technological processes should also be checked.
The use of steam for enterprises as a single coolant for technological processes, heating, ventilation and hot water supply is allowed with a feasibility study.
7.2 The maximum design temperature of network water at the outlet of the heat source, in heat networks and heat receivers is established on the basis of technical and economic calculations.
If there is a load of hot water supply in closed heat supply systems, the minimum temperature of the network water at the outlet of the heat source and in the heat networks should ensure the possibility of heating the water supplied to the hot water supply to the normalized level.
7.3 The temperature of the network water returned to thermal power plants with combined heat and power generation is determined by a feasibility study. The temperature of the network water returned to the boiler rooms is not regulated.
7.4 When calculating the schedules of heating water temperatures in district heating systems, the beginning and end of the heating period at the average daily outdoor temperature are taken:
8 °С in areas with an estimated outdoor air temperature for heating design up to minus 30 °С and an average calculated internal air temperature of heated buildings of 18 °С;
10 °C in areas with an estimated outdoor air temperature for heating design below minus 30 °C and an average design temperature of the indoor air of heated buildings of 20 °C.
The average design temperature of the internal air of heated industrial buildings is 16 °С.
7.5 If heat receivers in heating and ventilation systems do not have automatic individual temperature control devices inside the premises, heat carrier temperature control should be used in heat networks:
central quality according to the heating load, according to the joint load of heating, ventilation and hot water supply - by changing the temperature of the coolant at the heat source depending on the outside air temperature;
central qualitative-quantitative for the joint load of heating, ventilation and hot water supply - by regulating both the temperature and the flow of network water at the heat source.
The central qualitative-quantitative regulation at the heat source can be supplemented by group quantitative regulation at heat points, mainly during the transition period of the heating season, starting from the break point of the temperature graph, taking into account the schemes for connecting heating, ventilation installations and hot water supply, pressure fluctuations in the heat supply system, the presence and locations of storage tanks, heat storage capacity of buildings and structures.
7.6 With the central qualitative and quantitative regulation of heat supply for heating water in hot water supply systems of consumers, the temperature of the water in the supply pipeline should be:
for closed heat supply systems - not less than 70 °С;
for open heat supply systems - at least 60 °C.
With central qualitative-quantitative regulation according to the combined load of heating, ventilation and hot water supply, the break point of the water temperature graph in the supply and return pipelines should be taken at the outside air temperature corresponding to the break point of the heating load control graph.
7.7 In heat supply systems, if the consumer has heat in the heating and ventilation systems of individual devices for controlling the indoor air temperature by the amount of water flowing through the network water receivers, central qualitative and quantitative regulation should be used, supplemented by group quantitative regulation at heating points in order to reduce fluctuations in hydraulic and thermal regimes in specific quarterly (microdistrict) systems within the limits that ensure the quality and stability of heat supply.
7.8 For separate water heating networks from one heat source to enterprises and residential areas, it is allowed to provide different heat carrier temperature charts.
7.9 In buildings for public and industrial purposes, for which a decrease in air temperature at night and during non-working hours is possible, regulation of the temperature or flow rate of the heat carrier in heat points should be provided.
7.10 In residential and public buildings, in the absence of thermostatic valves for heating devices, automatic control according to the temperature schedule should be provided to maintain the average temperature of the internal air in the building.
7.11 It is not allowed to use for heat networks the schedules for regulating the release of heat "with cutoff" by temperature.

BUILDING REGULATIONS

HEATING NETWORK

SNiP 3.05.03-85

INTRODUCED by the Ministry of Energy of the USSR.

PREPARED FOR APPROVAL by the Main Technical Regulation of the Gosstroy of the USSR (N. A. Shishov).

With the entry into force of SNiP 3.05.03-85 "Heat networks", SNiP III-30-74 "Water supply, sewerage and heat supply. External networks and structures" becomes invalid.

When using a normative document, the approved changes in building codes and rules and state standards should be taken into account.

These rules apply to the construction of new, expansion and reconstruction of existing heating networks transporting hot water with a temperature of t≤ 200 °C and pressure P y ≤ 2.5 MPa (25 kgf / cm 2) and steam temperature t≤ 440 °C and pressure R y ≤ 6.4 MPa (64 kgf / cm 2) from the source of thermal energy to heat consumers (buildings, structures).

1. GENERAL PROVISIONS

1.1. When building new, expanding and reconstructing existing heating networks, in addition to the requirements of working drawings, work plans (PPR) and these rules, the requirements of SNiP 3.01.01-85, SNiP 3.01.03-84, SNiP III-4-80 and standards .

1.2. Works on the manufacture and installation of pipelines, which are subject to the requirements of the Rules for the Arrangement and Safe Operation of Steam and Hot Water Pipelines of the USSR Gosgortekhnadzor (hereinafter referred to as the Rules of the USSR Gosgortekhnadzor), must be carried out in accordance with the indicated Rules and the requirements of these rules and regulations.

1.3. Completed heat networks should be put into operation in accordance with the requirements of SNiP III-3-81.

2. EXCAVATION

2.1. Earthworks and foundation works must be carried out in accordance with the requirements of SNiP III-8-76. SNiP 3.02.01-83, SN 536-81 and this section.

2.2. The smallest trench bottom width for channelless pipe laying should be equal to the distance between the outer side edges of the insulation of the outermost heat pipelines

networks (associated drainage) with the addition on each side for pipelines with a nominal diameter D y up to 250 mm - 0.30 m, over 250 to 500 mm - 0.40 m, over 500 to 1000 mm - 0.50 m; the width of the pits in the trench for welding and insulating pipe joints during channelless laying of pipelines should be taken equal to the distance between the outer side faces of the insulation of the outermost pipelines with the addition of 0.6 m on each side, the length of the pits - 1.0 m and the depth from the bottom edge of the pipeline insulation - 0 .7 m, unless other requirements are justified by the working drawings.

2.3. The smallest width of the bottom of the trench in the case of channel laying of heat networks should be equal to the width of the channel, taking into account the formwork (in monolithic sections), waterproofing, associated drainage and drainage devices, the trench fastening structure with the addition of 0.2 m. In this case, the trench width should be at least 1 .0 m

If it is necessary for people to work between the outer edges of the channel structure and the walls or slopes of the trench, the clear width between the outer edges of the channel structure and the walls or slopes of the trench must be at least: 0.70 m for trenches with vertical walls and 0.30 m for trenches with slopes.

2.4. Backfilling of trenches during channelless and channel laying of pipelines should be carried out after preliminary testing of pipelines for strength and tightness, complete completion of insulation and construction and installation works.

Backfilling must be carried out in the specified technological sequence:

padding of sinuses between pipelines of channelless laying and the base;

simultaneous uniform backfilling of the sinuses between the walls of trenches and pipelines with channelless laying, as well as between the walls of the trench and channel, chamber with channel laying to a height of at least 0.20 m above pipelines, channels, chambers;

backfilling of the trench to design marks.

Backfilling of trenches (pits) to which additional external loads (except for the own weight of the soil) are not transferred, as well as trenches (pits) at intersections with existing underground utilities, streets, roads, driveways, squares and other structures of settlements and industrial sites should be carried out in accordance with the requirements of SNiP III-8-76.

2.5. After turning off the temporary dewatering devices, the channels and chambers must be visually inspected for the absence of groundwater in them.

3. CONSTRUCTIONS AND INSTALLATION OF BUILDING STRUCTURES

3.1. The construction and installation of building structures should be carried out in accordance with the requirements of this section and the requirements of:

SNiP III-15-76 - during the construction of monolithic concrete and reinforced concrete structures of foundations, supports for pipelines, chambers and other structures, as well as when monolithic joints;

SNiP III-16-80 - when installing prefabricated concrete and reinforced concrete structures;

SNiP III-18-75 - during the installation of metal structures of supports, superstructures for pipelines and other structures;

SNiP III-20-74-for waterproofing channels (chambers) and other building structures (structures);

SNiP III-23-76 - when protecting building structures from corrosion.

3.2. The outer surfaces of the elements of channels and chambers supplied to the route must be coated with a coating or glued waterproofing in accordance with the working drawings.

The installation of channel elements (chambers) in the design position should be carried out in the technological sequence linked to the project for the installation and preliminary testing of pipelines for strength and tightness.

Support pads for sliding supports of pipelines must be installed at the distances provided for in SNiP II-G.10-73* (II-36-73*).

3.3. Monolithic fixed shield supports must be made after the installation of pipelines in the shield support section.

3.4. In places where pipelines of channelless laying enter channels, chambers and buildings (structures), cases of bushings must be put on the pipes during their installation.

At the inlets of underground pipelines into buildings, devices must be made (in accordance with the working drawings) to prevent the penetration of gas into buildings.

3.5. Before installing the upper trays (plates), the channels must be cleared of soil, debris and snow.

3.6. The deviation of the slopes of the bottom of the heat network channel and drainage pipelines from the design one is allowed by ± 0.0005, while the actual slope must be at least the minimum allowable according to SNiP II-G.10-73* (II-36-73*) .

The deviation of the installation parameters of other building structures from the design ones must comply with the requirements of SNiP III-15-76. SNiP III-16-80 and SNiP III-18-75.

3.7. The construction organization project and the work execution project should provide for the advanced construction of drainage pumping stations and water outlet devices in accordance with the working drawings.

3.8. Before laying in the trench, drainage pipes must be inspected and cleaned of soil and debris.

3.9. Layer-by-layer filtering of drainage pipelines (except for pipe filters) with gravel and sand must be carried out using inventory separating forms.

3.10. The straightness of the sections of drainage pipelines between adjacent wells should be checked by looking at the light with a mirror before and after backfilling the trench. The pipe circumference reflected in the mirror must have the correct shape. The permissible horizontal deviation from the circle should not exceed 0.25 of the pipe diameter, but not more than 50 mm in each direction.

Deviation from the correct form of a circle along the vertical is not allowed.

4. PIPING INSTALLATION

4.1. The installation of pipelines must be carried out by specialized installation organizations, while the installation technology must ensure high operational reliability of the pipelines.

4.2. Parts, elements of pipelines (compensators, sumps, insulated pipes, as well as pipeline assemblies and other products) must be manufactured centrally (at the factory, workshops, workshops) in accordance with standards, specifications and project documentation.

4.3. The laying of pipelines in a trench, channel or on above-ground structures should be carried out according to the technology provided for by the project for the production of works and excluding the occurrence of residual deformations in pipelines, violation of the integrity of the anti-corrosion coating and thermal insulation by using appropriate mounting devices, correct placement of simultaneously operating hoisting machines and mechanisms.

The design of fastening mounting devices to pipes must ensure the safety of the coating and insulation of pipelines.

4.4. The laying of pipelines within the shield support must be carried out using pipes of the maximum delivery length. In this case, the welded transverse seams of the pipelines should, as a rule, be located symmetrically with respect to the shield support.

4.5. Laying pipes with a diameter of more than 100 mm with a longitudinal or spiral seam should be carried out with a displacement of these seams by at least 100 mm. When laying pipes with a diameter of less than 100 mm, the offset of the joints must be at least three times the thickness of the pipe wall.

Longitudinal seams must be located within the upper half of the circumference of the pipes to be laid.

Steeply bent and stamped pipe bends may be welded together without a straight section.

Welding of branch pipes and bends into welded joints and bent elements is not allowed.

4.6. When installing pipelines, movable supports and hangers must be displaced relative to the design position by the distance indicated in the working drawings, in the direction opposite to the movement of the pipeline in working condition.

In the absence of data in the working drawings, the movable supports and hangers of horizontal pipelines must be displaced, taking into account the correction for the outdoor temperature during installation, by the following values:

sliding supports and fastening elements of hangers to the pipe - by half of the thermal elongation of the pipeline at the point of fastening;

rollers of roller bearings - by a quarter of thermal elongation.

4.7. Spring hangers during installation of pipelines must be tightened in accordance with the working drawings.

During hydraulic testing of steam pipelines with a diameter of 400 mm or more, an unloading device should be installed in spring hangers.

4.8. Pipe fittings must be installed in a closed state. Flanged and welded fittings must be made without tension in the pipelines.

The deviation from perpendicularity of the plane of the flange welded to the pipe with respect to the axis of the pipe should not exceed 1% of the outer diameter of the flange, but be no more than 2 mm at the top of the flange.

4.9. Bellows (wavy) and stuffing box expansion joints should be mounted assembled.

When laying underground heating networks, the installation of expansion joints in the design position is allowed only after preliminary tests of pipelines for strength and tightness, backfilling of channelless pipelines, channels, chambers and shield supports.

4.10. Axial bellows and stuffing box compensators should be installed on pipelines without breaking the compensator axes and pipeline axes.

Permissible deviations from the design position of the connecting pipes of expansion joints during their installation and welding should not exceed those specified in the technical specifications for the manufacture and supply of expansion joints.

4 .11. When mounting bellows compensators, their twisting relative to the longitudinal axis and sagging under the action of their own weight and the weight of adjacent pipelines are not allowed. Slinging expansion joints should be done only by the branch pipes.

4.12. The installation length of bellows and stuffing box expansion joints must be taken from the working drawings, taking into account the correction for the outside air temperature during installation.

Stretching expansion joints to the installation length should be carried out using the devices provided for by the design of the expansion joints, or tension mounting devices.

4.13. Stretching of the U-shaped compensator should be performed after the completion of the installation of the pipeline, quality control of welded joints (except for the closing joints used for tension) and fixing the structures of fixed supports.

The expansion joint must be stretched to the value specified in the working drawings, taking into account the correction for the outside air temperature when welding the closing joints.

The expansion joint must be stretched simultaneously from both sides at the joints located at a distance of at least 20 and not more than 40 pipeline diameters from the axis of symmetry of the expansion joint, using clamping devices, unless other requirements are justified by the project.

On the section of the pipeline between the joints used for stretching the expansion joint, it is not necessary to carry out preliminary displacement of supports and hangers in comparison with the project (working draft).

4.14. Immediately before assembling and welding pipes, it is necessary to visually inspect each section for the absence of foreign objects and debris in the pipeline.

4.15. The deviation of the slope of pipelines from the design is allowed by ± 0.0005. In this case, the actual slope must be at least the minimum allowable according to SNiP II-G.10-73 * (II-36-73 *) .

The movable supports of the pipelines must be adjacent to the supporting surfaces of the structures without gap and distortion.

4.16. When performing installation work, the following types of concealed work are subject to acceptance with the preparation of survey reports in the form given in SNiP 3.01.01-85: preparation of the surface of pipes and welded joints for anti-corrosion coating; implementation of anticorrosive coating of pipes and welded joints.

An act should be drawn up on the stretching of compensators in the form given in the mandatory Appendix 1.

4.17. Protection of heat networks from electrochemical corrosion must be carried out in accordance with the Instructions for the protection of heat networks from electrochemical corrosion, approved by the USSR Ministry of Energy and the RSFSR Ministry of Housing and Communal Services and agreed with the USSR State Construction Committee.

5. ASSEMBLY, WELDING AND QUALITY CONTROL

WELDED JOINTS

GENERAL PROVISIONS

5.1. Welders are allowed to tack and weld pipelines if they have documents for the right to perform welding work in accordance with the Rules for the certification of welders approved by the USSR Gosgortekhnadzor.

5.2. Before being allowed to work on welding joints of pipelines, the welder must weld a tolerance joint under production conditions in the following cases:

with a break in work for more than 6 months;

when welding pipelines with a change in the group of steel, welding consumables, technology or welding equipment.

On pipes with a diameter of 529 mm or more, it is allowed to weld half the perimeter of the tolerance joint; at the same time, if the tolerance joint is a vertical fixed joint, the ceiling and vertical sections of the seam should be welded.

The tolerance joint must be of the same type with the production one (the definition of the same type of joint is given in the Rules for the certification of welders of the USSR Gosgortekhnadzor).

The tolerance joint is subject to the same types of control that are subject to production welded joints in accordance with the requirements of this section.

MANUFACTURING JOBS

5.3. The welder is obliged to knock out or build up a brand at a distance of 30-50 mm from the joint from the side accessible for inspection.

5.4. Before assembling and welding, it is necessary to remove the end caps, clean the edges and the inner and outer surfaces of the pipes adjacent to them to a width of at least 10 mm.

5.5. Welding methods, as well as types, structural elements and dimensions of welded joints of steel pipelines must comply with GOST 16037-80.

5.6. Joints of pipelines with a diameter of 920 mm or more, welded without the remaining backing ring, must be made with welding of the weld root inside the pipe. When welding inside the pipeline, the responsible contractor must be issued a work permit for the performance of high-risk work. The procedure for issuing and the form of the work permit must comply with the requirements of SNiP III-4-80.

5.7. When assembling and welding pipe joints without a backing ring, the offset of the edges inside the pipe should not exceed:

for pipelines that are subject to the requirements of the Rules of the USSR Gosgortekhnadzor - in accordance with these requirements;

for other pipelines - 20% of the pipe wall thickness, but not more than 3 mm.

At the joints of pipes assembled and welded on the remaining backing ring, the gap between the ring and the inner surface of the pipe should not exceed 1 mm.

5.8. Assembly of pipe joints for welding should be carried out using mounting centering devices.

Straightening smooth dents at the ends of pipes for pipelines that are not subject to the requirements of the USSR Gosgortekhnadzor Rules is allowed if their depth does not exceed 3.5% of the pipe diameter. Sections of pipes with deeper dents or tears should be cut out. The ends of pipes with nicks or chamfers with a depth of 5 to 10 mm should be cut off or corrected by surfacing.

5.9. When assembling a joint using tacks, their number should be for pipes with a diameter of up to 100 mm - 1-2, with a diameter of more than 100 to 426 mm - 3-4. For pipes with a diameter of more than 426 mm, tacks should be placed every 300-400 mm around the circumference.

Tacks should be evenly spaced around the perimeter of the joint. The length of one tack for pipes with a diameter of up to 100 mm - 10-20 mm, a diameter of more than 100 to 426 mm - 20-40, a diameter of more than 426 mm - 30-40 mm. The height of the tack should be at the wall thickness S up to 10 mm - (0.6-0.7) S, but not less than 3 mm, with a greater wall thickness - 5-8 mm.

The electrodes or welding wire used for tacks must be of the same grade as for welding the main seam.

5.10. Welding of pipelines, which are not subject to the requirements of the Rules of the USSR Gosgortekhnadzor, is allowed to be carried out without heating the welded joints:

at an outside temperature of up to minus 20 ° C - when using carbon steel pipes with a carbon content of not more than 0.24% (regardless of the pipe wall thickness), as well as low-alloy steel pipes with a wall thickness of not more than 10 mm;

at an outside temperature of up to minus 10 °C - when using pipes made of carbon steel with a carbon content of more than 0.24%, as well as pipes made of low-alloy steel with a wall thickness of more than 10 mm.

When the outside air temperature is very low, welding should be carried out in special booths, in which the air temperature in the area of the welded joints should be maintained not lower than the specified one.

It is allowed to carry out welding work in the open air with heating of the pipe ends to be welded over a length of at least 200 mm from the joint to a temperature of at least 200 °C. After welding is completed, a gradual decrease in the temperature of the joint and the adjacent pipe zone should be ensured by covering them with an asbestos sheet or using another method.

Welding (at negative temperature) of pipelines that are subject to the requirements of the Rules of the USSR State Technical Supervision Service must be carried out in compliance with the requirements of these Rules.

In case of rain, wind and snowfall, welding work may only be carried out if the welder and the welding site are protected.

5.11. Welding of galvanized pipes should be performed in accordance with SNiP 3.05.01-85.

5.12. Before welding pipelines, each batch of welding consumables (electrodes, welding wire, fluxes, shielding gases) and pipes must be subjected to incoming inspection:

for the presence of a certificate with verification of the completeness of the data given in it and their compliance with the requirements of state standards or technical specifications;

for the presence on each box or other packaging of an appropriate label or tag with verification of the data given on it;

for the absence of damage (damage) to the packaging or the materials themselves. If damage is found, the question of the possibility of using these welding consumables must be decided by the organization performing the welding;

on the technological properties of the electrodes in accordance with GOST 9466-75 or departmental regulations approved in accordance with SNiP 1.01.02-83.

5.13. When applying the main seam, it is necessary to completely cover and digest the potholders.

QUALITY CONTROL

5.14. Quality control of welding works and welded joints of pipelines should be carried out by:

checking the serviceability of welding equipment and measuring instruments, the quality of the materials used;

operational control during assembly and welding of pipelines;

external inspection of welded joints and measurements of weld dimensions;

checking the continuity of joints by non-destructive methods of control - radiographic (X-ray or gamma rays) or ultrasonic flaw detection in accordance with the requirements of the Rules of the USSR Gosgortekhnadzor, GOST 7512-82, GOST 14782-76 and other standards approved in the prescribed manner. For pipelines that are not subject to the USSR Gosgortekhnadzor Rules, it is allowed to use magnetographic testing instead of radiographic or ultrasonic testing;

mechanical tests and metallographic studies of control welded joints of pipelines, which are subject to the requirements of the Rules of the Gosgortekhnadzor of the USSR, in accordance with these Rules;

strength and tightness tests.

5.15. During the operational quality control of welded joints of steel pipelines, it is necessary to check the compliance with the standards of structural elements and dimensions of welded joints (blunting and cleaning of edges, the size of the gaps between the edges, the width and strengthening of the weld), as well as the technology and mode of welding, the quality of welding materials, tacks and weld seam.

5.16. All welded joints are subject to external inspection and measurement.

Joints of pipelines welded without backing ring with welding of the root of the seam are subjected to external inspection and measurement of the dimensions of the seam outside and inside the pipe, in other cases - only outside. Before inspection, the weld and adjacent pipe surfaces must be cleaned of slag, splashes of molten metal, scale and other contaminants to a width of at least 20 mm (on both sides of the weld).

The results of an external examination and measurement of the dimensions of welded joints are considered satisfactory if:

there are no cracks of any size and direction in the seam and the adjacent area, as well as undercuts, sagging, burns, unwelded craters and fistulas;

the dimensions and number of volumetric inclusions and recessions between the rollers do not exceed the values given in Table. one;

the dimensions of lack of penetration, concavity and excess penetration at the root of the weld of butt joints made without the remaining backing ring (if it is possible to inspect the joint from inside the pipe) do not exceed the values given in Table. 2.

Joints that do not meet the listed requirements are subject to correction or removal.

Table 1

	The maximum allowable linear size of the defect, mm	The maximum allowable number of defects for any 100 mm weld length
Volumetric inclusion of a rounded or elongated shape with a nominal wall thickness of the welded pipes in butt joints or a smaller leg of the weld in fillet joints, mm:

over 5.0 to 7.5


Recession (deepening) between the beads and scaly structure of the weld surface at the nominal wall thickness of the welded pipes in butt joints or with a smaller leg of the weld in fillet joints, mm:
		Not limited

table 2

5.17. Welded joints are subjected to continuity testing by non-destructive testing methods:

pipelines that are subject to the requirements of the USSR Gosgortekhnadzor Rules, with an outer diameter of up to 465 mm - in the amount provided for by these Rules, with a diameter of more than 465 to 900 mm - in the amount of at least 10% (but not less than four joints), with a diameter of more than 900 mm - in a volume of at least 15% (but not less than four joints) of the total number of joints of the same type made by each welder;

pipelines that are not subject to the requirements of the USSR Gosgortekhnadzor Rules, with an outer diameter of up to 465 mm - in the amount of at least 3% (but not less than two joints), with a diameter of more than 465 mm - in the amount of 6% (but not less than three joints) of the total number of the same type of joints performed by each welder; in the case of checking the continuity of welded joints using magnetographic testing, 10% of the total number of joints subjected to testing must be checked, in addition, by radiographic method.

5.18. 100% of welded joints of pipelines of heating networks laid in impassable channels under the carriageway, in cases, tunnels or technical corridors together with other engineering communications should be subjected to non-destructive control methods. and also at intersections:

railways and tram tracks - at a distance of at least 4 m, electrified railways - at least 11 m from the axis of the outermost track;

railways of the general network - at a distance of at least 3 m from the nearest subgrade structure;

motorways - at a distance of at least 2 m from the edge of the carriageway, the reinforced roadside strip or the sole of the embankment;

underground - at a distance of at least 8 m from the structures;

power, control and communication cables - at a distance of at least 2 m;

gas pipelines - at a distance of at least 4 m;

main gas pipelines and oil pipelines - at a distance of at least 9 m;

buildings and structures - at a distance of at least 5 m from walls and foundations.

5.19. Welded seams should be rejected if cracks, non-welded craters, burns, fistulas, as well as lack of penetration at the root of the seam made on the backing ring are found during testing by non-destructive testing methods.

5.20. When checking by radiographic method the welds of pipelines, which are subject to the requirements of the Rules of the Gosgortekhnadzor of the USSR, pores and inclusions, the dimensions of which do not exceed the values \u200b\u200bspecified in Table. 3.

Table 3

The height (depth) of lack of penetration, concavity and excess penetration at the root of the joint weld, made by one-sided welding without a backing ring, should not exceed the values \u200b\u200bspecified in Table. 2.

Permissible defects in welds according to the results of ultrasonic testing are considered to be defects, measured characteristics, the number of which does not exceed those indicated in Table. 4.

Table 4

Notes: 1. A defect is considered to be large if its nominal length exceeds 5.0 mm with a wall thickness of up to 5.5 mm and 10 mm with a wall thickness of more than 5.5 mm. If the conditional length of the defect does not exceed the specified values, it is considered small.

2. In electric arc welding without a backing ring with one-sided access to the seam, the total conditional length of defects located at the root of the seam is allowed up to 1/3 of the pipe perimeter.

3. The amplitude level of the echo signal from the measured defect should not exceed the amplitude level of the echo signal from the corresponding artificial corner reflector ("notch") or an equivalent segmental reflector.

5.21 . For pipelines that are not subject to the requirements of the Rules of the Gosgortekhnadzor of the USSR, pores and inclusions whose dimensions do not exceed the maximum allowable in accordance with GOST 23055-78 for class 7 welded joints, as well as lack of penetration, concavity and excess penetration are considered acceptable defects in the radiographic method of control at the root of the weld, made by one-sided electric arc welding without a backing ring, the height (depth) of which should not exceed the values \u200b\u200bspecified in Table. 2.

5 .22. If non-destructive testing methods reveal unacceptable defects in the welds of pipelines that are subject to the requirements of the USSR Gosgortekhnadzor Rules, a repeated quality control of the welds established by these Rules should be carried out, and in the welds of pipelines that are not subject to the requirements of the Rules, in a double number of joints according to compared with that specified in clause 5.17.

In the event that unacceptable defects are detected during re-inspection, all joints made by this welder should be checked.

5.23. Correction by local sampling and subsequent welding (without re-welding the entire joint) is subject to sections of the weld with unacceptable defects, if the dimensions of the sample after removing the defective section do not exceed the values \u200b\u200bspecified in Table. 5.

Welded joints, in the seams of which, in order to correct the defective area, it is required to make a sample with the dimensions of the pain allowed according to Table. 5 must be completely removed.

Table 5

Note. When correcting several sections in one connection, their total length may exceed that indicated in Table. 5 not more than 1.5 times with the same depth standards.

5.24. Undercuts should be corrected by surfacing thread rollers with a width of not more than 2.0 - 3.0 mm. Cracks must be drilled at the ends, cut down, carefully cleaned and welded in several layers.

5.25. All repaired areas of welded joints should be checked by visual inspection, radiographic or ultrasonic inspection.

5.26. On the executive drawing of the pipeline, drawn up in accordance with SNiP 3.01.03-84, the distances between welded joints, as well as from wells, chambers and subscriber inputs to the nearest welded joints, should be indicated.

6. THERMAL INSULATION OF PIPELINES

6.1. Installation of heat-insulating structures and protective coatings must be carried out in accordance with the requirements of SNiP III-20-74 and this section.

6.2. Welded and flanged joints should not be insulated to a width of 150 mm on both sides of the joints before testing pipelines for strength and tightness.

6.3. The possibility of performing insulation work on pipelines subject to registration in accordance with the Rules of the USSR Gosgortekhnadzor must be agreed with the local authority of the USSR Gosgortekhnadzor before performing tests for strength and tightness.

6.4. When performing filler and backfill insulation during channelless laying of pipelines, it is necessary to provide for temporary devices in the project for the production of works to prevent the pipeline from floating up, as well as from getting into the soil insulation.

7. TRANSITIONS OF HEAT NETWORKS THROUGH DRIVES AND ROADS

7.1. The performance of work at the underground (above-ground) crossing of railway and tram tracks, roads, city passages by heating networks should be carried out in accordance with the requirements of these rules, as well as SNiP III-8-76.

7.2. When puncturing, punching, horizontal drilling or other methods of trenchless laying of cases, the assembly and tacking of the sections (pipes) of the case must be performed using a centralizer. The ends of the welded links (pipes) must be perpendicular to their axes. Fractures of the axes of the links (pipes) of the cases are not allowed.

7.3. Reinforced shotcrete-concrete anti-corrosion coating of cases during their trenchless laying should be made in accordance with the requirements of SNiP III-15-76.

7.4. Pipelines within the case should be made of pipes of the maximum delivery length.

7.5. The deviation of the axis of transition cases from the design position for gravity condensate pipelines should not exceed:

vertically - 0.6% of the length of the case, provided that the design slope of the condensate pipelines is ensured;

horizontally - 1% of the length of the case.

The deviation of the transition case axis from the design position for the remaining pipelines should not exceed 1% of the case length.

8. TESTING AND FLUSHING (BLOWING) OF PIPING

GENERAL PROVISIONS

8.1. After completion of construction and installation works, pipelines must be subjected to final (acceptance) tests for strength and tightness. In addition, condensate pipelines and pipelines of water heating networks must be washed, steam pipelines - purged with steam, and pipelines of water heating networks with an open heat supply system and hot water supply networks - washed and disinfected.

Pipelines laid without channels and in impassable channels are also subject to preliminary tests for strength and tightness in the course of construction and installation works.

8.2. Preliminary testing of pipelines should be carried out before installing stuffing box (bellows) compensators, sectional valves, closing channels and backfilling pipelines without channel laying and channels.

Preliminary testing of pipelines for strength and tightness should be carried out, as a rule, in a hydraulic way.

At negative temperatures of the outside air and the impossibility of heating water, as well as in the absence of water, it is allowed, in accordance with the project for the production of works, to perform preliminary tests by pneumatic means.

It is not allowed to perform pneumatic tests of above-ground pipelines, as well as pipelines laid in the same channel (section) or in the same trench with existing utilities.

8.3. Pipelines of water heat networks should be tested with a pressure equal to 1.25 working pressure, but not less than 1.6 MPa (16 kgf / cm 2), steam pipelines, condensate pipelines and hot water supply networks - with a pressure equal to 1.25 working pressure, unless other requirements are justified project (working draft).

8.4. Before performing tests for strength and tightness, it is necessary:

to carry out quality control of welded joints of pipelines and correction of detected defects in accordance with the requirements of Sec. 5;

disconnect the tested pipelines from the existing ones and from the first stop valves installed in the building (structure) with plugs;

install plugs at the ends of the tested pipelines and instead of stuffing box (bellows) compensators, sectional valves during preliminary tests;

provide access throughout the tested pipelines for their external inspection and inspection of welds for the duration of the tests;

fully open fittings and bypass lines.

The use of shut-off valves to disconnect the tested pipelines is not allowed.

Simultaneous preliminary tests of several pipelines for strength and tightness are allowed to be carried out in cases justified by the work design.

8.5. Pressure measurements when testing pipelines for strength and tightness should be made using two duly certified (one - control) spring pressure gauges of class at least 1.5 with a body diameter of at least 160 mm and a scale with a nominal pressure of 4/3 of the measured pressure.

8.6. Testing of pipelines for strength and tightness (density), their purging, washing, disinfection must be carried out according to technological schemes (agreed with operating organizations) that regulate the technology and safety of work (including the boundaries of protected zones).

8.7. On the results of testing pipelines for strength and tightness, as well as on their flushing (purging), acts should be drawn up in the forms given in mandatory appendices 2 and 3.

HYDRAULIC TESTS

8.8. Piping tests should be carried out in compliance with the following basic requirements:

test pressure must be provided at the top point (mark) of the pipelines;

the water temperature during testing should not be lower than 5 °C;

at a negative outside temperature, the pipeline must be filled with water at a temperature not exceeding 70 ° C and it must be possible to fill and empty it within 1 hour;

when gradually filling with water, air must be completely removed from the pipelines;

the test pressure must be maintained for 10 minutes and then reduced to working pressure;

at operating pressure, the pipeline must be inspected along its entire length.

8.9. The results of hydraulic tests for the strength and tightness of the pipeline are considered satisfactory if during their implementation there was no pressure drop, no signs of rupture, leakage or fogging in welds, as well as leaks in the base metal, flange joints, fittings, compensators and other elements of pipelines , there are no signs of shift or deformation of pipelines and fixed supports.

PNEUMATIC TESTS

8.10. Pneumatic tests should be carried out for steel pipelines with a working pressure of not more than 1.6 MPa (16 kgf / cm 2) and temperatures up to 250 ° C, mounted from pipes and parts tested for strength and tightness (density) by manufacturers in accordance with GOST 3845-75 (at the same time, the factory test pressure for pipes, fittings, equipment and other products and parts of the pipeline must be 20% higher than the test pressure adopted for the installed pipeline).

The installation of cast iron fittings (except for ductile iron valves) is not allowed for the duration of the test.

8.11. Filling the pipeline with air and raising the pressure should be done smoothly at a rate of no more than 0.3 MPa (3 kgf / cm 2) per 1 hour. Visual inspection of the route [entrance to the security (dangerous) zone, but without descending into the trench] is allowed at a pressure value , equal to 0.3 test, but not more than 0.3 MPa (3 kgf / cm 2).

For the period of inspection of the route, the pressure increase must be stopped.

When the test pressure is reached, the pipeline must be held to equalize the air temperature along the length of the pipeline. After equalizing the air temperature, the test pressure is maintained for 30 minutes and then gradually decreases to 0.3 MPa (3 kgf / cm 2), but not higher than the working pressure of the coolant; at this pressure, pipelines are inspected with a mark of defective places.

Leaks are identified by the sound of escaping air, by bubbling when welding joints and other areas are covered with soapy emulsion, and by other methods.

Defects are eliminated only when the excess pressure is reduced to zero and the compressor is turned off.

8.12. The results of preliminary pneumatic tests are considered satisfactory if during their conduct there was no pressure drop on the pressure gauge, no defects were found in welds, flange joints, pipes, equipment and other elements and products of the pipeline, there are no signs of shear or deformation of the pipeline and fixed supports.

8.13. Pipelines of water networks in closed heat supply systems and condensate pipelines should, as a rule, be subjected to hydropneumatic flushing.

Hydraulic flushing is allowed with reuse of flushing water by passing it through temporary sumps installed in the direction of water movement at the ends of the supply and return pipelines.

Flushing, as a rule, should be carried out with process water. Flushing with utility and drinking water is allowed with justification in the project for the production of works.

8.14. Pipelines of water networks of open heat supply systems and hot water supply networks must be flushed hydropneumatically with drinking-quality water until the flushing water is completely clarified. Upon completion of flushing, the pipelines must be disinfected by filling them with water containing active chlorine at a dose of 75-100 mg / l with a contact time of at least 6 hours. Pipelines with a diameter of up to 200 mm and a length of up to 1 km are allowed, in agreement with local sanitary authorities. epidemiological service, do not expose to chlorination and limit yourself to washing with water that meets the requirements of GOST 2874-82.

After washing, the results of laboratory analysis of samples of wash water must comply with the requirements of GOST 2874-82. A conclusion is drawn up on the results of washing (disinfection) by the sanitary and epidemiological service.

8.15. The pressure in the pipeline during flushing should not be higher than the working one. The air pressure during hydropneumatic flushing should not exceed the working pressure of the coolant and be no higher than 0.6 MPa (6 kgf / cm 2).

Water velocities during hydraulic flushing must not be lower than the design coolant velocities indicated in the working drawings, and during hydropneumatic flushing, exceed the calculated ones by at least 0.5 m/s.

8.16. Steam pipelines must be purged with steam and vented to the atmosphere through specially installed purge pipes with shutoff valves. To warm up the steam pipeline, all start-up drains must be open before purging. The heating rate should ensure the absence of hydraulic shocks in the pipeline.

The steam velocities during the blowing of each section must be at least the operating velocities for the design parameters of the coolant.

9. ENVIRONMENTAL PROTECTION

9.1. During the construction of new, expansion and reconstruction of existing heating networks, environmental protection measures should be taken in accordance with the requirements of SNiP 3.01.01-85 and this section.

9.2. It is not allowed without agreement with the relevant service: to carry out excavation at a distance of less than 2 m to tree trunks and less than 1 m to shrubs; movement of goods at a distance of less than 0.5 m to crowns or tree trunks; storage of pipes and other materials at a distance of less than 2 m to tree trunks without the installation of temporary enclosing (protective) structures around them.

9.3. Flushing of pipelines in a hydraulic way should be carried out with the reuse of water. Emptying of pipelines after washing and disinfection should be carried out at the places indicated in the project for the production of works and agreed with the relevant services.

9.4. The territory of the construction site after the completion of construction and installation work must be cleared of debris.

APPENDIX 1

Mandatory

ABOUT STRETCHING COMPENSATORS

_______________________ "_____" _________________ 19_____

Commission consisting of:

______________________________________________________________________________

(last name, first name, patronymic, position)

______________________________________________________________________________

1. An extension of the compensators listed in the table was presented for inspection and acceptance in the area from the chamber (picket, mine) No. ______ to the chamber (picket, mine) No. ______.

______________________________________________________________________________

COMMISSION DECISION

The works were performed in accordance with the design and estimate documentation, state standards, building codes and regulations and meet the requirements for their acceptance.

(signature)

APPENDIX 2

Mandatory

ON TESTING PIPELINES

FOR STRENGTH AND TIGHTNESS

_______________________ "_____" ____________ 19____

Commission consisting of:

representative of the construction and installation organization _________________________________

______________________________________________________________________________

(last name, first name, patronymic, position)

representative of the technical supervision of the customer ____________________________ ______ ____

______________________________________________________________________________

(last name, first name, patronymic, position)

______________________________________________________________________________

(last name, first name, patronymic, position)

inspected the work performed by ____________________________________________

______________________________________________________________________________

(name of construction and installation organization)

and drew up this act as follows:

1. _________________________________ were presented for examination and acceptance.

_______________________________________________________________________________

(hydraulic or pneumatic)

pipelines tested for strength and tightness and listed in the table, in the section from the chamber (picket, mine) No. _______________________________________ to the chamber

(picket, mines) No. ______________________________ of route _____________________________

Length ______________ m.

(pipeline name)

2. The work was carried out according to the design and estimate documentation ____________________________

______________________________________________________________________________

(name of design organization, drawing numbers and date of drawing up)

COMMISSION DECISION

Representative of the construction and installation organization ________________

(signature)

Representative of the technical supervision of the customer ___________ __________

(signature)

APPENDIX 3

Mandatory

ON FLUSHING (BLOWING) OF PIPELINES

g.____________________"_____"_______________19_____

Commission consisting of:

representative of the construction and installation organization _________________________________

______________________________________________________________________________

(last name, first name, patronymic, position)

representative of the technical supervision of the customer ______________________________________

______________________________________________________________________________

(last name, first name, patronymic, position)

representative of the operating organization ______________________________________

______________________________________________________________________________

(last name, first name, patronymic, position)

inspected the work performed by _____________________________________________

______________________________________________________________________________

(name of construction and installation organization)

and drew up this act as follows:

1. Flushing (purging) of pipelines in the section from the chamber (picket, mine) No. ____________________________________________ to the chamber

(picket, mine) No. ______________ of the route __________________________________________

______________________________________________________________________________

(pipeline name)

length ____________________ m.

Flushing (purging) performed _________________________________________________

______________________________________________________________________________

(medium name, pressure, flow rate)

2. The work was carried out according to the design and estimate documentation ____________________________

______________________________________________________________________________

(name of design organization, drawing numbers and date of drawing up)

COMMISSION DECISION

The works were performed in accordance with the design estimates, standards, building codes and regulations and meet the requirements for their acceptance.

Representative of the construction and installation organization ________________

(signature)

Representative of the technical supervision of the customer _____________________

(signature)

Representative of the operating organization _____________________

SNiP 41-02-2003

APPENDIX B (mandatory)

Table B.1 - Vertical distances

Structures and engineering networks	The smallest clear distances vertically, m

To the water supply, drain, gas pipeline, sewerage	0,2
Up to armored communication cables	0,5
Up to power and control cables up to 35 kV	0.5 (0.25 in cramped conditions) - subject to the requirements of note 5
To oil-filled cables with a voltage of St. 110 kV	1.0 (0.5 in cramped conditions) - subject to the requirements of note 5
Up to the telephone sewer block or up to the armored communication cable in pipes	0,15
To the sole of the railroad tracks of industrial enterprises	1,0
The same, railways of the general network	2,0
» tram lines	1,0
To the top of the road surface of public roads of categories I, II and III	1,0
To the bottom of a ditch or other drainage structures or to the base of an embankment of a railway subgrade (if heating networks are located under these structures)	0,5
To metro facilities (if heating networks are located above these facilities)	1,0

To the head of railroads	Dimensions "C", "Sp", "Su" according to GOST 9238 and GOST 9720
To the top of the carriageway	5,0
To the top of the footpaths	2,2
To parts of the contact network of the tram	0,3
Same, trolleybus	0,2
To overhead power lines with the largest sag of wires at voltage, kV:
up to 1	1,0

Notes
1 Deepening of heat networks from the ground surface or road surface (except for motor roads of categories I, II and III) should be taken at least:
a) to the top of the ceilings of channels and tunnels - 0.5 m;
b) to the top of the ceilings of the chambers - 0.3 m;
c) up to the top of the channelless laying shell 0.7 m. In the impassable part, ceilings of chambers and ventilation shafts for tunnels and channels protruding above the ground are allowed to a height of at least 0.4 m;
d) at the input of heat networks into the building, it is allowed to take penetrations from the ground surface to the top of the overlap of channels or tunnels - 0.3 m and to the top of the channelless laying shell - 0.5 m;
e) at a high level of groundwater, it is allowed to provide for a decrease in the depth of channels and tunnels and the location of ceilings above the ground to a height of at least 0.4 m, if the conditions for the movement of vehicles are not violated.
2 When laying above-ground heating networks on low supports, the clear distance from the earth's surface to the bottom of the thermal insulation of pipelines must be, m, not less than:
with a group of pipes up to 1.5 m wide - 0.35;
with a group of pipes more than 1.5 m wide - 0.5.
3 When laying underground, heat networks at the intersection with power, control and communication cables can be located above or below them.
4 In case of channelless laying, the clear distance from water heating networks of an open heat supply system or hot water supply networks to sewer pipes located below or above the heating networks is assumed to be at least 0.4 m.
5 The temperature of the soil at the intersection of heat networks with electric cables at a depth of laying power and control cables with a voltage of up to 35 kV should not increase by more than 10 ° C in relation to the highest average monthly summer ground temperature and by 15 ° C - to the lowest average monthly winter ground temperature at a distance of up to 2 m from the outermost cables, and the temperature of the soil at the depth of the oil-filled cable should not rise by more than 5 ° C in relation to the average monthly temperature at any time of the year at a distance of up to 3 m from the outermost cables.
6 Deepening of heat networks in places of underground crossing of railways of the general network in heaving soils is determined by calculation from the conditions under which the influence of heat releases on the uniformity of frost heaving of the soil is excluded. If it is impossible to ensure the specified temperature regime due to the deepening of heating networks, ventilation of tunnels (channels, cases), replacement of heaving soil at the intersection or above-ground laying of heating networks is provided.
7 Distances to a telephone duct or to an armored communication cable in pipes should be specified according to special standards.
8 In places of underground intersections of heat networks with communication cables, telephone sewerage units, power and control cables with voltage up to 35 kV, it is allowed, with appropriate justification, to reduce the vertical distance in the light when installing reinforced thermal insulation and observing the requirements of paragraphs 5, 6, 7 of these notes.

Table B.2 - Horizontal distances from underground water heating networks of open heat supply systems and hot water supply networks to sources of possible pollution

Source of pollution

The smallest clear distances horizontally, m

1. Constructions and pipelines of household and industrial sewage: when laying heat networks in channels and tunnels when laying heat networks without channels D y ≤ 200 mm The same, D y > 200 mm

2. Cemeteries, landfills, cattle burial grounds, irrigation fields: in the absence of groundwater in the presence of groundwater and in filtering soils with the movement of groundwater towards heating networks

3. Cesspools and garbage pits: in the absence of groundwater in the presence of groundwater and in filtering soils with the movement of groundwater towards heating networks

1,0 1,5 3,0

Note - When sewerage networks are located below heat networks with parallel laying, horizontal distances should be taken at least as differences in the marks of the networks, above heat networks - the distances indicated in the table should increase by the difference in laying depth.

Table B.3 - Horizontal distances from the building structures of heat networks or pipeline insulation shells for channelless laying to buildings, structures and engineering networks

		The smallest clear distances, m
	Underground laying of heating networks
To the foundations of buildings and structures: when laying in channels and tunnels and non-subsidence soils (from the outer wall of the tunnel channel) with a diameter
	D< 500	2,0
	D y \u003d 500-800	5,0
	D y \u003d 900 or more	8,0

	D< 500	5,0
	D y ≥ 500	8,0
b) for channelless laying in non-subsidence soils (from channelless laying shells) with pipe diameter, mm:

	D< 500	5,0
	D y ≥ 500	7,0
The same, in subsiding soils of type I with:
	D y ≤ 100	5,0
	D y > 100 doD y<500	7,0
	D y ≥ 500	8,0
To the axis of the nearest track of the 1520 mm gauge railway		4.0 (but not less than the depth of the heating network trench up to

Buildings, structures and engineering networks
	mound soles)
The same, 750 mm track	2,8
To the nearest railway subgrade structure	3.0 (but not less than depth
roads	trenches of the heating network up to
	grounds for extreme
	structures)
To the axis of the nearest path of the electrified railway	10,75
roads
To the axis of the nearest tram track	2,8
To the side stone of the street of the road (edge of the carriageway,	1,5
reinforced roadside)
To the outer edge of the ditch or the bottom of the road embankment	1,0
To the foundations of fences and pipeline supports	1,5
Up to outdoor lighting masts and poles and communication networks	1,0
To the foundations of the supports of the overpass bridges	2,0
To the foundations of the poles of the contact network of railways	3,0
The same trams and trolleybuses	1,0
Up to power and control cables up to 35 kV and	2.0 (see note 1)
oil-filled cables (up to 220 kV)
To the foundations of overhead power transmission lines at
voltage, kV (when approaching and crossing):
up to 1	1,0
St. 1 to 35	2,0
St. 35	3,0
To the telephone sewer block, armored cable	1,0
connections in pipes and up to radio transmission cables
Before the water pipes	1,5
The same, in subsiding soils of type I	2,5
Before drains and rainwater	1,0
To industrial and household sewerage (with closed	1,0
heating system)
To gas pipelines with pressure up to 0.6 MPa during laying	2,0
heating networks in channels, tunnels, as well as with channelless
laying with accompanying drainage
The same, more than 0.6 to 1.2 MPa	4,0
To gas pipelines with pressure up to 0.3 MPa with channelless	1,0
laying heating networks without associated drainage
The same, more than 0.3 to 0.6 MPa	1,5
The same, more than 0.6 to 1.2 MPa	2,0
Up to the tree trunk	2.01 (see note 10)
Down to the bushes	1.0 (see note 10)
To channels and tunnels for various purposes (including up to	2,0
edges of canals of irrigation networks - ditches)
To subway structures when lining from the outside	5.0 (but not less than depth
adhesive insulation	trenches of the heating network up to
	building foundations)
The same, without pasting waterproofing	8.0 (but not less than depth
	trenches of the heating network up to
	building foundations)
To the fencing of surface subway lines	5

Buildings, structures and engineering networks	The smallest clear distances, m
To the tanks of automobile filling stations (gas stations): a) with channelless laying b) with channel laying (provided that ventilation shafts are installed on the heating network channel)	10,0 15,0
Above-ground laying of heating networks
To the nearest railway subgrade structure To the axis of the railway track from intermediate supports (when crossing railways) To the axis of the nearest tram track To the side stone or to the outer edge of the highway ditch To the overhead power line with the largest deviation of wires at voltage, kV: St. 1 to 20 35-110 150 220 330 500 Up to tree trunk Up to residential and public buildings< 0,63 МПа, конденсатных тепловых сетей при диаметрах труб, мм: Д у от 500 до 1400 Д у от 200 до 500 Д у < 200 До сетей горячего водоснабжения То же, до паровых тепловых сетей: Р у от 1,0 до 2,5 МПа св. 2,5 до 6,3 МПа	3 Dimensions "C", "Sp", "Su" according to GOST 9238 and GOST 9720 2.8 0.5 (See note 8) 1 3 4 4,5 5 6 6,5 2,0 25 (see note 9) 20 (see note 9) 10 (see note 9)
Notes 1 It is allowed to reduce the distance given in Table EL3, subject to the condition that in the entire area where the heating networks approach the cables, the temperature of the soil (accepted according to climatic data) at the place where the cables pass at any time of the year will not increase by more than 10 ° compared to the average monthly temperature С for power and control cables with voltage up to 10 kV and for 5 °С - for power control cables with voltage 20 - 35 kV and oil-filled cables up to 220 kV. 2 When laying heat and other engineering networks in common trenches (with their simultaneous construction), it is allowed to reduce the distance from heat networks to water supply and sewerage systems to 0.8 m when all networks are located at the same level or with a difference in laying marks of not more than 0.4 m. 3 For heat networks laid below the foundation of the foundations of supports, buildings, structures, the difference in elevations should be additionally taken into account, taking into account the natural slope of the soil, or measures should be taken to strengthen the foundations. 4 With parallel laying of underground heating and other engineering networks at different depths, the ones given in Table B.3. distances should increase and be taken not less than the difference in the laying of networks. In cramped laying conditions and the impossibility of increasing the distance, measures should be taken to protect engineering networks from collapse during the repair and construction of heating networks. 5 When parallel laying heat and other engineering networks, it is allowed to reduce the distances given in table R3_ to structures on networks (wells, chambers, niches, etc.) to a value of at least 0.5 m, providing for measures to ensure the safety of structures during the construction - installation works. 6 Distances to special communication cables must be specified in accordance with the relevant standards. 7 The distance from the ground pavilions of heating networks for the placement of shut-off and control valves (in the absence of pumps in them) to residential buildings is taken at least 15 m. In particularly cramped conditions, it can be reduced to 10 m. 8 When parallel laying of above-ground heat networks with an overhead power line with a voltage of more than 1 to 500 kV outside settlements, the horizontal distance from the outermost wire should be taken not less than the height of the support. 9 When laying temporary (up to 1 year of operation) water heating networks (bypasses) above ground, the distance to residential and public buildings can be reduced while ensuring the safety of residents (100% control of welds, testing of pipelines by 1.5 of the maximum working pressure, but not less than 1.0 MPa, the use of fully covered steel valves, etc.). 10 In exceptional cases, if it is necessary to lay heating networks underground closer than 2 m from trees, 1 m from shrubs and other green spaces, the thickness of the heat-insulating layer of pipelines should be taken twice.

Rules for the technical operation of thermal power plants Team of authors

6. HEAT NETWORKS

6.1. Technical requirements

6.1.1. The method of laying new heating networks, building structures, thermal insulation must comply with the requirements of current building codes and regulations and other regulatory and technical documents. The choice of pipeline diameters is carried out in accordance with the feasibility study.

6.1.2. Pipelines of heating networks and hot water supply with a 4-pipe laying should, as a rule, be located in one channel with separate thermal insulation of each pipeline.

6.1.3. The slope of pipelines of heat networks should be provided for at least 0.002, regardless of the direction of movement of the coolant and the method of laying heat pipelines. The routing of pipelines should exclude the formation of stagnant zones and provide the possibility of complete drainage.

The slope of heat networks to individual buildings during underground laying is taken from the building to the nearest chamber. In some areas (when crossing communications, laying on bridges, etc.), it is allowed to lay heating networks without a slope.

6.1.4. At the intersections of heating networks during their underground laying in channels or tunnels with gas pipelines, devices for sampling for leakage are provided on heating networks at a distance of no more than 15 m on both sides of the gas pipeline.

The passage of gas pipelines through the building structures of chambers, impassable channels and niches of heating networks is not allowed.

6.1.5. When heating networks intersect existing water supply and sewage networks located above pipelines of heating networks, as well as when crossing gas pipelines, it is necessary to install cases on pipelines of water supply, sewerage and gas at a length of 2 m on both sides of the intersection (in the light).

6.1.6. At the inlets of pipelines of heating networks into buildings, it is necessary to provide devices that prevent the penetration of water and gas into buildings.

6.1.7. At the intersection of above-ground heat networks with high-voltage power lines, it is necessary to ground (with the resistance of grounding devices not more than 10 Ohms) all electrically conductive elements of heat networks located at a distance of 5 m in each direction from the axis of the projection of the edge of the structure of the overhead power line on the ground surface.

6.1.8. In places where heat pipelines are laid, construction of buildings, storage, planting of trees and perennial shrubs is not allowed. The distance from the projection on the earth's surface of the edge of the building structure of the heating network to the structures is determined in accordance with building codes and regulations.

6.1.9. The materials of pipes, fittings, supports, compensators and other elements of pipelines of heating networks, as well as methods for their manufacture, repair and control must comply with the requirements established by the Gosgortekhnadzor of Russia.

6.1.10. For pipelines of heating networks and heating points at a water temperature of 115 ° C and below, at a pressure of up to 1.6 MPa inclusive, it is allowed to use non-metallic pipes if their quality meets sanitary requirements and corresponds to the parameters of the coolant.

6.1.11. Welded joints of pipelines are subjected to non-destructive testing in accordance with the volumes and requirements established by the Gosgortekhnadzor of Russia.

6.1.12. 100% of welded joints of pipelines of heating networks laid in impassable channels under the carriageway of roads, in cases, tunnels or technical corridors together with other engineering communications, as well as at intersections should be subjected to non-destructive control methods:

railways and tramways - at a distance of at least 4 m, electrified railways - at least 11 m from the axis of the outermost track;

railways of the general network - at a distance of at least 3 m from the nearest subgrade structure;

motorways - at a distance of at least 2 m from the edge of the carriageway, the reinforced roadside strip or the sole of the embankment;

underground - at a distance of at least 8 m from the structures;

power, control and communication cables - at a distance of at least 2 m;

gas pipelines - at a distance of at least 4 m;

main gas pipelines and oil pipelines - at a distance of at least 9 m;

buildings and structures - at a distance of at least 5 m from walls and foundations.

6.1.13. When monitoring the quality of the connecting welding joint of a pipeline with an existing main (if there is only one shut-off valve between them, as well as when monitoring no more than two joints made during repair), the strength and density test can be replaced by checking the welded joint with two types of control - radiation and ultrasonic. For pipelines that are not subject to the requirements established by the Gosgortekhnadzor of Russia, it is sufficient to check the continuity of welded joints using magnetographic control.

6.1.14. For all pipelines of heating networks, except for heating points and hot water supply networks, it is not allowed to use fittings:

from gray cast iron - in areas with an estimated outdoor temperature for heating design below minus 10 ° C;

from ductile iron - in areas with an estimated outdoor temperature for heating design below minus 30 ° C;

from high-strength cast iron in areas with an estimated outdoor temperature for heating design below minus 40 ° C;

from gray cast iron on drain, purge and drainage devices in all climatic zones.

6.1.15. It is not allowed to use shut-off valves as control valves.

6.1.16. It is allowed to use fittings made of brass and bronze on pipelines of heating networks at a coolant temperature not exceeding 250 °C.

6.1.17. Steel fittings are installed at the outlets of heating networks from heat sources.

6.1.18. The installation of shut-off valves is provided for:

on all pipelines of heat network outlets from heat sources, regardless of the parameters of heat carriers;

on pipelines of water networks D y 100 mm or more at a distance of no more than 1,000 m (sectional valves) with a jumper between the supply and return pipelines;

in water and steam heating networks at nodes on branch pipelines D y more than 100 mm, as well as at nodes on branch pipelines to individual buildings, regardless of the diameter of the pipeline;

on condensate pipelines at the inlet to the condensate collection tank.

6.1.19. On water heat networks with a diameter of 500 mm or more at a conditional pressure of 1.6 MPa (16 kgf / cm 2) or more, with a diameter of 300 mm or more at a conditional pressure of 2.5 MPa (25 kgf / cm 2) or more, on steam networks with a diameter of 200 mm or more at a conditional pressure of 1.6 MPa (16 kgf / cm 2) and more for valves and gates, bypass pipelines (bypasses) with shutoff valves are provided.

6.1.20. Gate valves and gates with a diameter of 500 mm or more are equipped with an electric drive. When laying aboveground heating networks, gate valves with electric drives are installed indoors or enclosed in casings that protect the fittings and the electric drive from atmospheric precipitation and exclude access to them by unauthorized persons.

6.1.21. At the lower points of pipelines of water heating networks and condensate pipelines, as well as sectioned sections, fittings with shutoff valves for draining water (drainage devices) are mounted.

6.1.22. From the steam pipelines of heating networks at low points and before vertical rises, condensate must be continuously drained through steam traps.

In the same places, as well as on straight sections of steam pipelines, after 400–500 m with a passing slope and after 200–300 m with a counter slope, a steam pipeline start-up drainage device is mounted.

6.1.23. To drain water from pipelines of water heating networks, waste wells are provided with water discharge into sewerage systems by gravity or mobile pumps.

When draining water into a domestic sewer, a water seal is installed on a gravity pipeline, and if a reverse flow of water is possible, an additional shut-off (check) valve is installed.

When laying pipelines above ground in an undeveloped area, for draining water, concrete pits should be provided with water drained from them by cuvettes, trays or pipelines.

6.1.24. To remove condensate from the permanent drains of the steam pipeline, it is possible to discharge condensate into the condensate collection and return system. It is allowed to drain it into the pressure condensate pipeline if the pressure in the drainage condensate pipeline is at least 0.1 MPa (1 kgf / cm 2) higher than in the pressure one.

6.1.25. At the highest points of pipelines of heat networks, including at each sectional section, fittings with shut-off valves for air release (air vents) must be installed.

6.1.26. In heat networks, reliable compensation for thermal elongation of pipelines should be provided. To compensate for thermal elongations, the following are used:

flexible expansion joints made of pipes (U-shaped) with pre-stretching during installation;

angles of rotation from 90 to 130 degrees (self-compensation); bellows, lens, stuffing box and sleeve.

Gland steel expansion joints are allowed to be used at P y not more than 2.5 MPa and a temperature not more than 300 ° C for pipelines with a diameter of 100 mm or more for underground laying and above-ground on low supports.

6.1.27. Stretching of the U-shaped compensator should be performed after the completion of the installation of the pipeline, quality control of welded joints (except for the closing joints used for tension) and fixing the structure of fixed supports.

The expansion joint is stretched by the value specified in the project, taking into account the correction for the outside air temperature when welding the closing joints.

An act should be drawn up on the stretching of compensators.

6.1.28. To control the parameters of the coolant, the heating network is equipped with selective devices for measuring:

temperatures in the supply and return pipelines before sectional valves and in the return pipeline of branches with a diameter of 300 mm or more before the valve along the flow of water;

water pressure in the supply and return pipelines before and after sectional valves and control devices, in the forward and return pipelines of branches before the valve;

steam pressure in the branch pipelines before the valve.

6.1.29. At control points of heating networks, local indicating instrumentation is installed to measure temperature and pressure in pipelines.

6.1.30. The outer surfaces of pipelines and metal structures of heating networks (beams, supports, trusses, overpasses, etc.) must be protected with resistant anti-corrosion coatings.

Commissioning of heat networks after completion of construction or major repairs without an external anti-corrosion coating of pipes and metal structures is not allowed.

6.1.31. For all pipelines of heat networks, fittings, flange connections, compensators and pipe supports, regardless of the temperature of the coolant and laying methods, thermal insulation should be performed in accordance with building codes and regulations that determine the requirements for thermal insulation of equipment and pipelines.

The materials and thickness of heat-insulating structures should be determined during design from the conditions for ensuring standard heat losses.

6.1.32. It is allowed in places not accessible to personnel, during a feasibility study, thermal insulation should not be provided for:

when laying return pipelines of heat networks in the premises D< 200 мм, если тепловой поток через неизолированные стенки трубопроводов учтен в проекте систем отопления этих помещений;

condensate pipelines when condensate is discharged into the sewer; condensate networks when they are jointly laid with steam networks in impassable channels.

6.1.33. Fittings, flange connections, manholes, compensators should be insulated if the equipment or pipeline is insulated.

Thermal insulation of flanged joints, fittings, sections of pipelines subjected to periodic control, as well as stuffing box, lens and bellows compensators, is provided as removable.

Heat networks laid outdoors, regardless of the type of laying, must be protected from moisture.

6.1.34. The design of thermal insulation must exclude deformation and slipping of the thermal insulation layer during operation.

On vertical sections of pipelines and equipment, every 1–2 m in height, it is necessary to carry out supporting structures.

6.1.35. For overhead pipelines when using heat-insulating structures made of combustible materials, 3 m long inserts made of non-combustible materials should be provided every 100 m of the pipeline length.

6.1.36. In places of installation of electrical equipment (pumping, heating points, tunnels, chambers), as well as in places of installation of fittings with electric drive, regulators and instrumentation, electric lighting is provided that complies with the rules for electrical installations.

The through channels of heating networks are equipped with forced-air and exhaust ventilation.

6.2. Exploitation

6.2.1. During the operation of heat network systems, the reliability of heat supply to consumers, the supply of heat carrier (water and steam) with flow rates and parameters in accordance with the temperature schedule and pressure drop at the inlet must be ensured.

The connection of new consumers to the heat networks of the energy supplying organization is allowed only if the heat source has a reserve of power and a reserve of throughput of the mains of the heat network.

6.2.2. The organization operating heat networks monitors the consumer's compliance with the specified heat consumption modes.

6.2.3. During the operation of heating networks, the access routes to the network facilities, as well as road surfaces and surface planning above underground structures, are maintained in proper condition, the serviceability of enclosing structures is ensured, preventing unauthorized persons from accessing equipment and shutoff and control valves.

6.2.4. Excavation of the route of pipelines of the heat network or the performance of work near them by outside organizations is allowed only with the permission of the organization operating the heat network, under the supervision of a person specially appointed by it.

6.2.5. The organization draws up and permanently stores: a heat network plan (large-scale);

operational and operational (calculation) schemes;

profiles of heating mains for each main line with a static pressure line;

list of gas hazardous chambers and passage channels.

Neighboring underground utilities (gas pipeline, sewerage, cables), electrified transport rail tracks and traction substations are plotted on the heat network plan in an area of at least 15 m from the projection on the ground surface of the edge of the building structure of the heat network or channelless pipeline on both sides of the route. On the plan of the heating network, the places and results of planned pits, places of emergency damage, flooding of the route and shifted sections are systematically marked.

The plan, schemes, profiles of heating mains and the list of gas hazardous chambers and channels are adjusted annually in accordance with the actual state of heating networks.

All changes are made under the signature of the responsible person, indicating his position and the date of the change.

Information about changes in diagrams, drawings, lists and the corresponding changes in instructions are brought to the attention of all employees (with an entry in the order log), for whom knowledge of these documents is mandatory.

6.2.6. On the plans, diagrams and piezometric graphs, the operational numbers of all heating mains, chambers (branch nodes), pumping stations, automatic control units, fixed supports, compensators and other structures of the heating network are indicated.

On operational (calculation) schemes, all consumer systems connected to the network are subject to numbering, and on operational schemes, in addition, sectional and shutoff valves.

The fittings installed on the supply pipeline (steam pipeline) are indicated by an odd number, and the fittings corresponding to it on the return pipeline (condensate pipeline) are indicated by the even number following it.

6.2.7. On the operational diagram of the heating network, all gas-dangerous chambers and passage channels are marked.

Gas hazardous chambers must have special signs, color hatches and be kept under reliable constipation.

Supervision of gas hazardous chambers is carried out in accordance with the safety rules in the gas industry.

6.2.8. The organization operating heat networks (heat supply organization) participates in the acceptance after installation and repair of heat networks, heat points and heat-consuming installations owned by the consumer.

Participation in the technical acceptance of consumer facilities consists in the presence of a representative of the heat supply organization during strength and density tests of pipelines and equipment of heating points connected to the heat supply networks of the heat supply organization, as well as heat consumption systems connected according to a dependent scheme. The organization operating heat networks keeps copies of test reports, as-built documentation indicating the main shut-off and control valves, air vents and drains.

6.2.9. After completion of construction and installation works (in case of new construction, modernization, reconstruction), major or current repairs with the replacement of sections of pipelines, pipelines of heat networks are tested for strength and density.

Pipelines laid in impassable channels or without channels are also subject to preliminary tests for strength and density in the course of work before installing stuffing box (bellows) compensators, sectional valves, closing channels and backfilling pipelines.

6.2.10. Preliminary and acceptance tests of pipelines are carried out with water. If necessary, in some cases, it is allowed to perform preliminary tests in a pneumatic way.

Pneumatic testing of above-ground pipelines, as well as pipelines laid in the same channel or in the same trench with existing utilities, is not allowed.

6.2.11. Hydraulic testing of pipelines of water heating networks in order to check the strength and density should be carried out with a test pressure with inclusion in the passport.

The minimum value of the test pressure during a hydraulic test is 1.25 working pressure, but not less than 0.2 MPa (2 kgf / cm 2).

The maximum value of the test pressure is set by the strength calculation according to the normative and technical documentation agreed with the Gosgortekhnadzor of Russia.

The value of the test pressure is chosen by the manufacturer (design organization) within the limits between the minimum and maximum values.

All newly installed pipelines of heating networks, controlled by the Gosgortekhnadzor of Russia, must be subjected to a hydraulic test for strength and density in accordance with the requirements established by the Gosgortekhnadzor of Russia.

6.2.12. When conducting hydraulic tests for the strength and density of heat networks, it is necessary to turn off the equipment of heat networks (stuffing box, bellows compensators, etc.), as well as sections of pipelines and connected heat-consuming power plants that are not involved in the tests, with plugs.

6.2.13. During operation, all heating networks must be tested for strength and density to detect defects no later than two weeks after the end of the heating season.

6.2.14. Strength and density tests are carried out in the following order:

disconnect the tested section of the pipeline from the existing networks;

at the highest point of the section of the pipeline under test (after filling it with water and venting), set the test pressure;

the pressure in the pipeline should be increased smoothly;

the pressure rise rate must be specified in the regulatory and technical documentation (hereinafter RTD) for the pipeline.

With a significant difference in geodetic marks on the test section, the value of the maximum allowable pressure at its lowest point is agreed with the design organization to ensure the strength of pipelines and the stability of fixed supports. Otherwise, the test of the site must be carried out in parts.

6.2.15. Strength and density tests should be carried out in compliance with the following basic requirements:

pressure measurement during testing should be carried out using two certified spring pressure gauges (one is a control one) of a class of at least 1.5 with a body diameter of at least 160 mm. The pressure gauge must be selected from the condition that the measured pressure value is in 2/3 of the instrument scale;

test pressure must be provided at the top point (mark) of the pipelines;

the water temperature must not be lower than 5 °C and not higher than 40 °C;

when filling with water, air must be completely removed from the pipelines;

the test pressure must be maintained for at least 10 minutes and then reduced to working pressure;

at operating pressure, a thorough inspection of pipelines along their entire length is carried out.

6.2.16. The test results are considered satisfactory if during the test there was no pressure drop and no signs of rupture, leakage or fogging were found in the welds, as well as leaks in the base metal, in valve bodies and glands, in flanged joints and other pipeline elements. In addition, there should be no signs of shifting or deformation of pipelines and fixed supports.

On the results of testing pipelines for strength and density, it is necessary to draw up an act of the established form.

6.2.17. Pipelines of heat networks before putting them into operation after installation, major or current repairs with the replacement of sections of pipelines are cleaned:

steam pipelines - purging with steam discharge into the atmosphere;

water networks in closed heat supply systems and condensate pipelines - hydropneumatic flushing;

water networks in open heat supply systems and hot water supply networks - hydropneumatic flushing and disinfection (in accordance with sanitary rules) followed by repeated flushing with drinking water. Repeated flushing after disinfection is carried out until the quality indicators of the discharged water are achieved, corresponding to the sanitary standards for drinking water.

It is necessary to draw up an act on the flushing (purging) of pipelines.

6.2.18. For flushing closed heat supply systems, it is allowed to use water from a drinking or technical water supply system; after flushing, water is removed from pipelines.

6.2.19. The connection of heat networks and heat consumption systems after installation and reconstruction is carried out on the basis of a permit issued by the state energy supervision authorities.

6.2.20. Filling of pipelines of heating networks, their washing, disinfection, turning on circulation, purging, heating of steam pipelines and other operations for the start-up of water and steam heating networks, as well as any testing of heating networks or their individual elements and structures are carried out according to a program approved by the technical manager of the organization and agreed with a source of heat, and, if necessary, with environmental authorities.

6.2.21. The start-up of water heating networks consists of the following operations:

filling pipelines with network water; establishment of circulation; network density checks;

switching on consumers and starting adjustment of the network.

Pipelines of heating networks are filled with water at a temperature not exceeding 70 ° C with the heat consumption systems turned off.

Pipelines should be filled with water at a pressure not exceeding the static pressure of the filled part of the heating network by more than 0.2 MPa.

In order to avoid hydraulic shocks and for better removal of air from pipelines, the maximum hourly water flow G b when filling pipelines of a heating network with a nominal diameter D y should not exceed the values \u200b\u200bspecified below:

Distribution networks should be filled after main pipelines are filled with water, and branches to consumers - after distribution networks are filled.

6.2.22. During the start-up period, it is necessary to monitor the filling and heating of pipelines, the condition of shut-off valves, stuffing box compensators, and drainage devices.

The sequence and speed of starting operations are carried out in such a way as to exclude the possibility of significant thermal deformations of pipelines.

The program for the start-up of heat networks takes into account the features of the start-up of a water heating network at negative outdoor temperatures (after a long emergency shutdown, overhaul or when starting up newly built networks).

The heating of network water when circulation is established should be carried out at a rate of not more than 30 ° C per hour.

In the event of damage to the launch pipelines or related equipment, measures are taken to eliminate these damages.

In the absence of devices for measuring the flow of the coolant, start-up adjustment is carried out according to the temperature in the return pipelines (until the temperature is equalized from all consumers connected to the network).

6.2.23. The start-up of steam networks consists of the following operations: warming up and purging steam pipelines;

filling and flushing of condensate pipelines; consumer connections.

6.2.24. Before the start of heating, all valves on the branches from the heated area are tightly closed. First, the main line is heated, and then its branches in turn. Small, slightly branched steam pipelines can be heated simultaneously throughout the entire network.

In the event of hydraulic shocks, the steam supply is immediately reduced, and with frequent and strong shocks, it stops completely until the condensate accumulated in it is completely removed from the heated section of the steam pipeline.

The heating rate of the steam pipeline is regulated by signs of the appearance of light hydraulic shocks (clicks). During heating, it is necessary to regulate its speed, while preventing the steam pipeline from slipping from the movable supports.

6.2.25. During the current operation of heat networks, it is necessary to: maintain all equipment, building and other structures of heat networks in good condition, conducting their inspection and repair in a timely manner;

observe the operation of compensators, supports, fittings, drains, air vents, instrumentation and other elements of equipment, timely eliminating the identified defects and leaks;

identify and restore destroyed thermal insulation and anti-corrosion coating;

remove water accumulating in channels and chambers and prevent groundwater and upland waters from getting there;

disable non-working sections of the network;

timely remove air from heat pipelines through air vents, prevent air from entering heat networks, maintaining the constantly necessary overpressure at all points of the network and heat consumption systems;

maintain cleanliness in the chambers in the passage channels, prevent unauthorized persons from staying in them;

take measures to prevent, localize and eliminate accidents and incidents in the operation of the heating network;

control corrosion.

6.2.26. To control the condition of the equipment of heat networks and thermal insulation, their modes of operation, heat pipelines and heat points are regularly bypassed according to the schedule. The bypass schedule provides for monitoring the condition of the equipment by both fitters and foremen.

The frequency of bypasses is set depending on the type of equipment and its condition, but at least 1 time per week during the heating season and 1 time per month during the non-heating period. Thermal cameras must be inspected at least once a month; chambers with drainage pumps - at least 2 times a week. Checking the performance of drainage pumps and their automatic activation is mandatory at each bypass.

The results of the inspection are recorded in the register of defects in thermal networks.

Defects that threaten an accident and an incident are eliminated immediately. Information about defects that do not pose a danger from the point of view of the reliability of the operation of the heating network, but which cannot be eliminated without disconnecting the pipelines, is entered in the bypass and inspection log of the heating networks, and to eliminate these defects during the next shutdown of the pipelines or during repairs - in the maintenance log . Control can be carried out remotely.

6.2.27. When bypassing the heating network and inspecting underground chambers, personnel are provided with a set of necessary tools, fixtures, lighting fixtures, and an explosion-proof gas analyzer.

6.2.28. To control the hydraulic and temperature conditions of heating networks and heat-consuming installations, it is necessary to check the pressure and temperature at the nodal points of the network using pressure gauges and thermometers during planned bypasses.

6.2.29. During the operation of heat networks, the leakage of the heat carrier must not exceed the norm, which is 0.25% of the average annual volume of water in the heat network and heat consumption systems connected to it per hour, regardless of their connection scheme, with the exception of hot water supply systems (hereinafter referred to as DHW) connected through water heater.

When determining the coolant leakage rate, the water consumption for filling heat pipelines and heat consumption systems during their scheduled repair and connecting new sections of the network and consumers should not be taken into account.

6.2.30. To control the density of equipment of heat sources, heat networks and heat consumption systems, it is allowed, in accordance with the established procedure, to use coloring leak indicators approved for use in heat supply systems.

6.2.31. At each heating network make-up node, the make-up water consumption corresponding to the normative leakage is determined, and instrumental accounting of the actual make-up water consumption is provided.

In case of leakage of the coolant exceeding the established norms, measures must be taken to detect the place of leakage and eliminate them.

6.2.32. In addition to testing for strength and density in organizations operating heating networks, they are tested for the maximum temperature of the coolant, to determine heat and hydraulic losses 1 time in 5 years.

All tests of thermal networks are carried out separately and in accordance with the current guidelines.

6.2.33. For each newly commissioned section of the heating network (regardless of the parameters of the coolant and the diameter of the pipelines), a passport of the established form is drawn up (Appendix 5). The passport keeps records of the duration of operation of pipelines and heating network structures, records are made of the results of all types of tests (except for annual strength and tightness tests at the end of the heating season), information is entered on repairs, reconstructions and technical examinations.

6.2.34. To monitor the condition of underground heat pipelines, heat-insulating and building structures, it is necessary to periodically drill on the heating network.

Planned drilling is carried out according to an annually drawn up plan approved by the person responsible for the good condition and safe operation of thermal power plants and (or) heating networks (technical manager) of the organization.

The number of annual drillings is set depending on the length of the network, the methods of laying and heat-insulating structures, the number of previously identified corrosion damage to pipes, and the results of tests for the presence of stray current potential.

At least one pit is provided for 1 km of the route.

On new sections of the network, drilling starts from the third year of operation.

6.2.35. Drilling is carried out first of all:

near places where corrosion damage to pipelines is recorded;

at intersections with drains, sewerage, water supply;

in areas located near open drains (cuvettes), passing under lawns or near curb stones of sidewalks;

in places with unfavorable hydrogeological conditions;

in areas with an alleged unsatisfactory condition of heat-insulating structures (as evidenced, for example, by thawed places along the heat pipeline route in winter);

in areas of channelless laying, as well as channel laying with thermal insulation without an air gap.

6.2.36. The dimensions of the pit are chosen based on the convenience of inspecting the opened pipeline from all sides. In channelless laying, the size of the pit along the bottom is at least 1.5x1.5 m; in channel gaskets, the minimum dimensions ensure the removal of floor slabs for a length of at least 1.5 m.

6.2.37. During the pit inspection, the insulation, pipeline under insulation and building structures are inspected. If there are noticeable traces of corrosion, it is necessary to clean the surface of the pipe and measure the thickness of the pipeline wall using an ultrasonic thickness gauge or flaw detector.

If the measurement results are doubtful, and if wall thinning is detected by 10% or more, it is necessary to make control drillings and determine the actual wall thickness.

If local thinning of the wall is detected by 10% of the design (initial) value, these sections are subjected to re-control in the repair campaign of the next year.

Sections with thinning of the pipeline wall by 20% or more must be replaced.

Based on the results of the inspection, an act is drawn up.

6.2.38. Works to protect heat networks from electrochemical corrosion are carried out by specialized organizations (divisions).

The operation of corrosion protection means and corrosion measurements are carried out in accordance with the current regulatory and technical documents.

6.2.39. To determine the corrosiveness of soils and the dangerous effects of stray currents, systematic inspections of pipelines of underground heating networks and electrical measurements for the potential of stray currents are carried out.

6.2.40. Electrical measurements on the routes of newly constructed and reconstructed heat networks are carried out by organizations that have developed a project for heat networks, or by specialized organizations that develop technical solutions for protecting heat networks from external corrosion.

Measurements of the electrical resistivity of soils are carried out as necessary to identify sections of the route of thermal networks of channelless laying in soils with high corrosiveness.

Corrosion measurements to determine the dangerous effect of stray currents on steel pipelines of underground heating networks should be carried out in the areas of influence of stray currents once every 6 months, as well as after each significant change in the mode of operation of power supply systems for electrified vehicles (changes in the schedule of operation of electric vehicles, changes in the location of traction substations, suction points, etc.) and the conditions associated with the development of a network of underground structures and sources of stray currents, the introduction of electrochemical protection equipment at adjacent structures.

In other cases, the measurement is made 1 time in 2 years.

6.2.41. Installations of electrochemical protection are subject to periodic technical inspection, verification of the effectiveness of their work and scheduled preventive maintenance.

Electrical protection installations are constantly kept in a state of full working capacity.

Preventive maintenance of electrochemical protection installations is carried out according to the schedule of technical inspections and preventive maintenance approved by the technical manager of the organization. The schedule provides for a list of types and volumes of technical inspections and repair work, the timing of their implementation, instructions for organizing accounting and reporting on the work performed.

6.2.42. Technical inspections and scheduled preventive repairs are carried out in the following terms:

technical inspection of cathode installations - 2 times a month, drainage installations - 4 times a month;

technical inspection with efficiency check - 1 time in 6 months;

maintenance - 1 time per year; overhaul - 1 time in 5 years.

All malfunctions in the operation of the electrochemical protection installation are eliminated within 24 hours after their discovery.

6.2.43. The effectiveness of the operation of drainage and cathode installations is checked 2 times a year, as well as with each change in the operating mode of electrochemical protection installations and with changes associated with the development of a network of underground structures and sources of stray currents.

6.2.44. The resistance to current spreading from the anode ground electrode system of the cathode station is measured in all cases when the operating mode of the cathode station changes dramatically, but at least once a year.

6.2.45. The total duration of breaks in the operation of electrochemical protection installations in heat networks cannot exceed 7 days during the year.

6.2.46. During the operation of electrically insulating flange joints, their technical inspections are carried out periodically, but at least once a year.

6.2.47. In water heating networks and condensate pipelines, systematic monitoring of internal corrosion of pipelines is carried out by analyzing network water and condensate, as well as by indicators of internal corrosion installed at the most characteristic points of heating networks (at the outlets from the heat source, at the end sections, at several intermediate nodes ). Checking indicators of internal corrosion is carried out during the repair period.

6.2.48. Every year, before the start of the heating season, all pumping stations must be subjected to comprehensive testing to determine the quality of repairs, the correct operation and interaction of all thermal and mechanical and electrical equipment, controls, automation, telemechanics, protection of heat supply system equipment and determine the degree of readiness of pumping stations for the heating season.

6.2.49. The current inspection of the equipment of automated pumping stations should be carried out every shift, checking the load of electrical equipment, the temperature of the bearings, the presence of lubricant, the condition of the seals, the operation of the cooling system, the presence of chart tapes in the recording devices.

6.2.50. At non-automated pumping stations, equipment is serviced every shift.

6.2.51. Before starting the pumps, and during their operation, once a shift, it is necessary to check the condition of the pumping and related equipment.

In drainage pumping stations, at least 2 times a week, the effect of the level regulator on the device for automatically turning on the pumps should be monitored.

6.2.52. During the operation of automatic regulators, periodic inspections of their condition, operation check, cleaning and lubrication of moving parts, adjustment and adjustment of regulatory bodies to maintain the specified parameters are carried out. Automation and technological protection devices for heating networks can be taken out of operation only by order of the technical manager of the organization, except for cases when individual protections are turned off during equipment start-up, provided for by local instructions.

6.2.53. The heating network is replenished with softened deaerated water, the quality indicators of which meet the requirements for the quality of network and make-up water for hot water boilers, depending on the type of heat source and heat supply system.

6.2.54. The heating systems connected according to an independent scheme are fed with water from the heating network.

6.2.55. The water pressure at any point of the supply line of water heating networks, heat points and at the upper points of directly connected heat consumption systems during the operation of network pumps must be higher than the saturated steam pressure of water at its maximum temperature by at least 0.5 kgf / cm 2.

6.2.56. The excess water pressure in the return line of water heating networks during the operation of network pumps must be at least 0.5 kgf / cm 2. The water pressure in the return line must not be higher than that allowed for heating networks, heating points and for directly connected heat consumption systems.

6.2.57. The idle heat network is filled only with deaerated water and must be under excess pressure of at least 0.5 kgf / cm 2 at the upper points of the pipelines.

6.2.58. For two-pipe water heating networks, the schedule of central quality regulation is provided as the basis for the heat supply mode.

If there is a hot water supply load, the minimum water temperature in the supply pipeline of the network is provided for closed heat supply systems not lower than 70 °C; for open hot water heating systems - not lower than 60 °C.

6.2.59. The water temperature in the supply line of the water heating network, in accordance with the schedule approved for the heat supply system, is set according to the average outdoor air temperature over a period of time within 12–24 hours, determined by the heat network dispatcher, depending on the length of the networks, climatic conditions and other factors.

Deviations from the specified mode at the heat source are provided for no more than:

according to the temperature of the water entering the heating network ± 3%;

by pressure in the supply pipeline ± 5%;

by pressure in the return pipeline ± 0.2 kgf / cm 2.

The deviation of the actual average daily temperature of the return water from the heating network may exceed the one specified by the schedule by no more than +5%. The decrease in the actual return water temperature compared to the schedule is not limited.

6.2.60. Hydraulic modes of water heating networks are developed annually for the heating and summer periods; for open heat supply systems during the heating season, the regimes are developed at maximum water intake from the supply and return pipelines and in the absence of water intake.

Measures to regulate water consumption at consumers are drawn up for each heating season.

The sequence of construction of new mains and pumping stations, provided for by the heat supply scheme, is determined taking into account the real increase in the connected heat load, for which the organization operating the heat network develops hydraulic modes of the heat supply system for the next 3–5 years.

6.2.61. For each control point of the heating network and at the recharge nodes, in the form of a regime map, the permissible values \u200b\u200bof the flow rates and pressures of water in the supply, return (and make-up) pipelines are set, corresponding to normal hydraulic regimes for the heating and summer periods.

6.2.62. In the event of an emergency interruption of the power supply to network and transfer pumps, the organization operating the heating network ensures that the pressure in the heating networks and heat consumption systems is within the permissible level. If it is possible to exceed this level, it is planned to install special devices that protect the heat supply system from water hammer.

6.2.63. Repair of heating networks is carried out in accordance with the approved schedule (plan) based on the results of the analysis of identified defects, damage, periodic inspections, tests, diagnostics and annual tests for strength and density.

The schedule of repair work is drawn up based on the condition of simultaneous repair of pipelines of the heating network and heating points.

Before carrying out repairs of heating networks, pipelines are freed from network water, channels must be drained. The temperature of the water pumped from waste wells must not exceed 40 °C. Descent of water from the chamber of thermal networks to the surface of the earth is not allowed.

6.2.64. In each organization operating heat networks (in each operational area, section), an instruction is drawn up, approved by the technical head of the organization, with a clearly developed operational plan of action in case of an accident at any of the heating mains or pumping station in relation to local conditions and network communications.

The instruction should provide for the procedure for disconnecting mains, distribution networks and branches to consumers, the procedure for bypassing chambers and heating points, possible switches for supplying heat to consumers from other mains, and have diagrams of possible emergency switching between mains.

Plans for the elimination of technological disturbances in the heating networks of cities and large settlements are coordinated with local authorities.

6.2.65. According to the developed switching schemes, the operating and maintenance personnel of heating networks are regularly trained according to the approved schedule (but at least once a quarter) to work out the clarity, sequence and speed of performing emergency operations with their reflection on the operational diagram.

6.2.66. To quickly carry out work to limit the spread of accidents in heating networks and eliminate damage, each operational area of the heating network provides the necessary supply of fittings and materials. Fittings installed on pipelines are provided for the same type in length and flanges.

The emergency supply of materials is stored in two places: the main part is stored in the pantry, and a certain amount of the emergency supply (consumables) is in a special cabinet at the disposal of the responsible person from the operational staff. Consumables used by operational personnel are replenished within 24 hours from the main part of the stock.

The stock of fittings and materials for each operational area of the heating network is determined depending on the length of the pipelines and the number of installed fittings in accordance with the emergency stock standards, a list of necessary fittings and materials is compiled, which is approved by those responsible for the good condition and safe operation of the organization's heating networks.

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