Proper fastening to building structures pipelines ensures their operational reliability. If existing installation standards are violated, the pipeline may be damaged and its durability reduced. In this case, the specifics of the materials from which the pipes are made should be taken into account. In particular, the possibility of their expansion with a change in temperature environment. Exactly physical properties materials determine the list technical requirements for fasteners.
Basic and special properties of fasteners
Vertical and horizontal pipelines are attached to building structures by means of fasteners - hangers and supports. Brackets, strips, clamps, consoles and embedded parts for fastening pipelines are involved in the installation process.
Fasteners must meet the following basic requirements:
- save high quality and reliability even in the process of repeated use for its intended purpose;
- ensure its functionality different conditions installation of the pipeline, including at increased loads;
- be unified and universal;
- have a mandatory high mechanical and corrosion resistance, capable of withstanding aggressive environmental influences.
In addition, the installation of support structures for fastening pipelines should not cause difficulties. It is necessary that working with suspensions and supports was easy and simple. This requirement ensures excellent workflow ergonomics.
Special requirements are imposed on the supporting structures when it is necessary to take into account the specifics of the material from which the pipes are made. When pinned polymer pipelines such special requirements must be taken into account.
- In straight sections, polymer structures can change their length due to the high coefficient of linear expansion of this material. In this case, the supporting structures should not interfere with the free movement of the pipeline. And this means that compensators with a special design of fixing clamps should be used.
- Unlike metal, polymers are particularly sensitive to mechanical damage. Therefore, parts that come into contact with such material must be smooth, devoid of sharp edges and burrs. A metal clamp with a screw is more often used in relation to steel structures, and in the case of polymers, flat clamps are used with a smooth inner surface, rounded edges and gaskets. Plastic clamps for fastening Fusioterm pipelines are popular.
- The strength, heat resistance and hardness of polymers, when compared with steel, are low. Therefore, pipelines from them cannot be used as load-bearing structures.
Polymer pipes not fixed in clamps on fixed supports. This leads to their damage.
Elements for fastening hydraulic pipelines produced in two design options. Without a solid base, if the ambient temperature air environment or transported liquid does not exceed 30°C, and with a base at more high temperatures.
Calculation of fasteners for pipelines
If the design does not require a solid base, then the gaps between the fasteners are set by calculation. At the same time, the design of the fasteners itself must withstand not only the weight of the pipeline, but also the liquid that will be transported through it. And this means that it must be strong enough and reliable.
In the absence of a single technical documentation should be guided by design standards that have been developed by a number of organizations specializing in this field. They are presented to users in the form of albums of drawings and OSTs. Fasteners are calculated based on:
- OST 36-17-85;
- CH 527-80;
- OST 95-761-79 and others.
In these documents, the distance between hangers and supports is indicated depending on the diameter of the pipelines, pressure, temperature of the transported liquid and the environment. SN 527-80 also takes into account the recommended distance to the surface of galleries, tunnels, channels and walls when attaching the pipeline to the wall. With increased density of the transported liquid, correction factors must be applied.
Types of fastening structures
Bearing fastening structures are divided into the following types:
- Fixed supports. When using this fastener, angular or linear movement of the fixed sections is not allowed.
- Guide supports. The use of this design allows displacement in only one direction. As a rule, only along the horizontal axis.
- Rigid pendants. Movement is allowed, but only in horizontal plane.
- Spring hangers and supports. Both vertical and horizontal movements are possible.
Types of fastening pipelines to the wall
Requirements for supports and hangers
If the fixation occurs between two fixed supports, the movements that can occur as a result of the change temperature conditions, mounting braces or displacement of supports, must be self-compensating. But such a compensating ability, as calculations show, is sometimes not enough. In this case, special compensators must be installed.
Pipe clamp equipped with screw/bolt
They are made from pipes of the same type and diameter as the structure as a whole. Most often they are performed in the form of the letters "P" or "G".
If the structure is fixed fixedly, the fasteners must withstand the weight of the pipeline itself, the fluid that moves through it, as well as axial loads generated by thermal deformation, vibrations and hydraulic shocks. When mounting products made of polymers, movable supports are most often used.
If the installation is carried out in fixed supports, restrictive rings or segments 10-20 mm wide are welded to the pipes, which are made from pieces of pipes of the same plastic. These segments or rings should be located on both sides of the support.
Choice of fasteners
Suitable fasteners are selected taking into account many factors. The choice depends on the location of the installation site, on the purpose of a particular system, and so on.
Fastening plastic pipe
Sometimes the pipe must be insulated from the source of cold or heat. If you use a simple clamp that fixes the area, then it will not provide the gap from the adjacent surface necessary to solve the problem. But, for example, an annular support, which has a threaded extension and a plate for fixing to the supporting surface, will completely eliminate the problem.
If you have to fix heavy cast iron pipes, then use special fasteners that can withstand heavy loads. For vertically located systems, it is installed on floors. Horizontally oriented systems are fixed not even one by one, but by groups of pipes laid on the console.
A competent approach to the selection and placement of fasteners allows for a long and efficient operation of the pipeline without fear of emergency situations. But do not forget about the economic component of this problem. After all, exceeding the necessary and sufficient number of elements can lead to an unjustified increase in the cost of the structure and complication installation work.
Video: pipeline fastening calculation
Aboveground gas pipelines should be laid on free-standing supports, whatnots and columns made of non-combustible materials or along the walls of buildings. In this case, laying is allowed:
On free-standing supports, columns, racks and whatnots - gas pipelines of all pressures;
Along the walls of industrial buildings with premises related to fire hazard to categories G and D - gas pipelines with pressure up to 0.6 MPa;
On the walls of public and residential buildings at least 3 degrees of fire resistance - gas pipelines with a pressure of up to 0.3 MPa;
On the walls public buildings and residential buildings of 4-5 degrees of fire resistance - gas pipelines low pressure with a nominal diameter of pipes, not more than 50 mm. The height of gas pipelines along the walls of residential and public buildings should be taken in agreement with the operating organization.
It is prohibited to lay transit gas pipelines:
On the walls of buildings of children's institutions, hospitals, sanatoriums, cultural and entertainment, leisure and religious institutions - gas pipelines of all pressures;
Along the walls of residential buildings - gas pipelines of medium and high pressure.
The connection of underground steel gas pipelines-inlets with the riser of the above-ground (basement) input must be welded using bent or sharply bent bends. Welded butt joints in sections of underground gas pipelines-inlets must be checked non-destructive methods control.
High-pressure gas pipelines up to 0.6 MPa are allowed to be laid along the walls, above windows and doorways of one-story and above the windows of the upper floors of industrial buildings with premises related to fire danger to categories D and D, as well as buildings of separate boiler houses.
It is not allowed to provide detachable connections and shut-off valves on gas pipelines under balconies and under window openings of residential and public buildings.
In a free area outside the passage of vehicles and the passage of people, it is allowed to lay gas pipelines on low supports at a height of at least 0.5 m, provided that one or more pipes are laid on the support. Gas pipelines at the places of exit from the ground should be enclosed in cases, the above-ground part of which should be at least 0.5 m. The end of the above-ground parts of the cases must be sealed with bitumen to prevent atmospheric precipitation from entering the annulus.
Distance to buildings and structures see table
In places where people pass, the height of the gas pipeline on supports is 2.2 m.
When laying a gas pipeline on supports closer than 2 m to the edge of the carriageway, it is necessary to provide a protective fence. The minimum distance of the protective gas pipeline to buildings must be at least 2 m. Gas pipelines are fastened to the supports using clamps.
Permissible spans between supports:
Pipe d- 20mm - 3 m
25mm - 3.5m
The laying of the gas pipeline along the walls is carried out using brackets according to the series 5.905-8 (Fastening the gas pipeline along the walls of the building). The distance between gas pipelines and walls should provide easy access for inspection and repair.
To combat corrosion, metal structures and pipes are painted twice with a preliminary application of a primer.
insulating flanges. Purpose and place of installation.
Insulating flange connection (IFS). The protection of gas pipelines with the help of IFS and inserts consists in the fact that the gas pipeline is divided into separate sections, due to which the conductivity of the pipe decreases, and at the same time the strength of the current flowing through the gas pipeline decreases and the solution of the issue of their protection is simplified.
The installation of the EIF at the inputs provides for the impossibility of electrical contact between the house and the gas pipeline. Installation of EIF on gas pipelines - inputs to the house are not higher than 2.2 m (usually 1.6-1.8 m from the ground for ease of maintenance).
Flange connections when installing gate valves, compensators must be shunted with permanent jumpers.
Placement of disconnecting devices on the gas pipeline.
Disconnecting devices on gas pipelines should be provided for:
At the inputs residential, public, industrial buildings, in front of outdoor gas-consuming installations (mobile boiler rooms, bitumen-digesting boilers, kilns for drying sand and firing building materials, etc.)
At the inputs to the hydraulic fracturing, at the outputs from the hydraulic fracturing with looped gas pipelines in systems with two or more hydraulic fracturing;
On branches of inter-settlement gas pipelines to settlements or enterprises;
On branches from gas distribution pipelines to individual microdistricts, quarters and individual groups of residential buildings;
For sectioning distribution gas pipelines of medium and high pressure for the possibility of performing emergency and repair work;
When gas pipelines cross water barriers, as well as one thread with a width of a water barrier with a low water horizon of 75 m or more;
When crossing pipelines railways common network and highways Category 1 and 2 disconnecting devices should be placed:
In front of the territories of industrial, municipal or other enterprises.
Disconnecting devices on external gas pipelines should be placed in wells, ground fireproof cabinets or fences, as well as on the walls of buildings. Wellless underground installation disconnecting devices, connected by welding, intended for installation without wells and requiring no maintenance.
Switching devices intended for installation on the walls of buildings should be placed at distances from doorways and opening window openings, not less than, m:
For low pressure gas pipelines - 0.5 m;
For gas pipelines of medium pressure horizontally - 1.0 m;
For high pressure gas pipelines up to 0.6 MPa horizontally -3.0 m.
Distances from disconnecting devices located on the walls of buildings on the gas pipeline to receiving devices supply ventilation must be at least 5 m horizontally. When the disconnecting devices are located at a height of more than 2.2 m
platforms made of non-combustible materials with stairs should be provided.
Purpose, device of shut-off and control valves?
Industrial pipeline fittings are:
1. shut-off
2. regulatory
3. safety
4. control
Shut-off valves are designed to turn on and off individual sections of pipelines during operation. It includes taps, valves, valves.
Control valves are designed to change the pressure or temperature, or the flow rate of the transported medium.
Safety fittings are designed to protect pipelines, gas equipment, tanks from excessive
high pressure, as well as to maintain required pressure in the pipeline.
Shut-off valves must be tight against external environment. Valves, cocks, gate valves and butterfly valves intended for gas supply systems as stop valves(disconnecting devices) must be designed for hydrocarbon gases. The tightness of the gates must correspond to class 1 according to GOST 9544.
Valves and butterfly valves must have rotation stops and position indicators "open-closed."
Stop valves are made of gray cast iron, ductile iron, carbon steel, copper-based alloys.
Shut-off valves in accordance with GOST 4666 must be marked on the body and have a distinctive color. The label must contain trademark manufacturer, conditional or operating pressure, nominal size and flow direction indicator, if necessary.
KPO on underground gas pipelines. Terms of inspection of gas pipelines. Paperwork.
Underground gas pipelines (made of metal and polyethylene pipes) in operation must be subject to technical inspection, incl. and complex instrumental examination. KPO, with the help of devices according to specially developed instructions, and if necessary, drilling is also carried out. During the technical examination
gas pipelines, the actual location of gas pipelines, the state of structures and equipment on them, tightness, condition protective coating and electrochemical protection.
When performing KPO, the following are checked:
location and, if necessary, the depth of the gas pipeline;
tightness of the gas pipeline;
continuity and condition of the protective coating.
Technical inspection of underground steel gas pipelines is carried out:
with a duration of operation up to 25 years - at least 1 time in 5 years. The first one a year after commissioning;
when operating for more than 25 years and before the expiration of the depreciation period of operation - at least 1 time in 3 years;
when included in the plan overhaul or replacement, as well as with a protective coating below the “highly reinforced” type - at least 1 time per year.
Extraordinary KPO of gas pipelines must be carried out:
If the service life exceeds for steel gas pipelines - 40 years, for p / et - 50 years;
If leaks or ruptures of welded joints, through corrosion damage are detected;
When the “gas pipeline-ground” potential drops to values below the minimum allowable, subject to a break in the operation of electrical protective installations for more than 1 month - in the zones of influence of stray currents and more than 6 months - in other cases provided for by DSTU B V.2.5-29:2006 " Engineering equipment houses and structures. External networks and facilities. Gas supply systems. Underground steel gas pipelines. General requirements to corrosion protection.
On gas pipelines with a protective coating lower than the "highly reinforced" type, in addition to KPO, control drilling should be carried out to determine the condition of the pipes and the quality of the welded joints. Technical inspection of the condition of polyethylene gas pipelines is carried out within the time limits established for steel gas pipelines.
At KPO, a worksheet of 2 copies is compiled, one is given to the foreman of the network section.
Drilling on the gas pipeline. Drilling assignment. The order of the work. Formulation of documentation.
Inspection of underground steel gas pipelines in order to determine the state of the protective coating, where the use of devices is hindered by industrial interference, is carried out by opening control pits on gas pipelines with a length of at least 1.5 m every 500 m.
The places of opening of the control pits, their number in the zones of industrial interference are determined gas company or an enterprise operating gas facilities on its own.
For visual inspection, the areas subject to the greatest corrosion hazard, the places where gas pipelines intersect with others, are selected. underground utilities, condensate collectors. At the same time, at least one pit should be opened for each kilometer of distribution gas pipelines and for every 200 m - a yard or intra-quarter gas pipeline, but at least one pit per passage, yard or quarter.
Checking tightness and detecting gas leaks from underground gas pipelines during the period of soil freezing, as well as in areas located under an improved road surfaces, should be done by drilling wells (or studding) followed by taking air samples from them.
On distribution gas pipelines and inlets, wells are drilled at the joints. In the absence of the location of the joints, wells should be drilled every 2 m.
The depth of drilling them in winter time should not be less than the depth of freezing of the soil, in warm time year - correspond to the depth of pipe laying. Wells are laid at a distance of at least 0.5 m from the gas pipeline wall.
When using highly sensitive gas detectors, it is allowed to reduce the depth of wells and place them along the axis of the gas pipeline, provided that the distance between the top of the pipe and the bottom of the well is at least 40 cm.
Application open fire to determine the presence of gas in wells is not allowed.
Pit inspection of polyethylene gas pipelines is carried out only at the installation sites of steel inserts.
For 1 km of gas distribution pipelines and for each quarterly distribution, at least 1 insert is checked. To be able to inspect the joints of the joints of a polyethylene gas pipeline with a steel insert, the length of the pit should be 1.5-2 m. The pits are opened using mechanisms or manually. Checking the insulation and metal of steel inserts must be carried out at least once every 5 years.
According to the results technical survey steel and polyethylene gas pipelines, a protocol should be drawn up, in which, taking into account the identified defects and assessing technical condition, a conclusion should be made on the possibility of further operation of the gas pipeline, the need for the timing of its repair and replacement. Information about the work performed and the results of the survey is entered in the passport of the gas pipeline.
Chapter 11. TECHNOLOGY OF INSTALLATION OF PIPELINES
The installation of pipelines should be carried out in accordance with the project, detailed drawings (KTD), the project for the production of works (PPR) and safety regulations. Installation of pipelines is carried out mainly with ready-made units manufactured in pipe preparation shops complete with fittings, as well as blocks of pipelines assembled at the installation site, with maximum mechanization of installation work. It is allowed to mount pipelines "in place" from individual pipes and parts only in exceptional cases.
§ 1. PREPARATORY WORKS
Before starting work on the installation of pipelines, the foreman of the fitters examines the working drawings, specifications, PPR and other technical documentation for the facility being prepared for installation. Having received the installation task, the workers must familiarize themselves in detail with the technical documentation and safety regulations. At the same time, they study the layout of pipelines, plans and dimensions of the building, drawings of apparatus and equipment piping, fastening of pipelines and supporting structures, specifications for products and fittings.
Prior to the installation of pipelines, the following preparatory work must be carried out:
compliance with the project for the installation of supporting structures for pipelines, installation of embedded parts for fastening pipelines, the presence of holes for pipelines in building structures, fixing fixed supports of free-standing supporting structures and overpasses was checked. Installation and sealing of embedded structures and openings for pipelines are provided for in the construction part of the project and must be carried out by the construction organization.
buildings, building structures, overpasses, flumes, trenches were accepted by the act from building organizations with a check of their construction readiness for the installation of pipelines and compliance with the design marks to which the pipelines are linked in the installation drawings. When accepting trenches, the compliance of their dimensions and marks with the design ones, the correctness of the slope arrangement, compliance with the slopes, the quality of the bed and the condition of the fasteners should be checked. The foundations of trenches in rocky soils must be leveled with a layer of sand or gravel with a thickness of at least 20 cm;
the compliance with the drawings of the types, dimensions and location of the fittings of the equipment to which the pipelines are connected, the accuracy of its installation in the axes and marks were checked. All deviations from the project must be recorded in the work log;
platforms for intermediate storage and enlargement of pipeline units were organized. Intermediate storage of pipes, parts and assemblies is carried out in open areas for each line separately and they are located so that free passage and access to them are provided for inspection, checking the marking and performing loading and unloading operations. When stored outdoors or indoors without wooden floor all mounting blanks, regardless of the nature of their installation, are laid on wooden linings with a height of at least 200 mm so that it is possible to tie them when they are submitted for installation. Ready-made pipeline assemblies are recommended to be delivered to objects in containers, which creates convenience during storage, on-site movement and loading and unloading operations. Near the places of storage of blanks, it is recommended to place signs indicating the number of the node and the number of the line according to the project;
workplaces, tools, mounting devices prepared; equipment for welding stations; the necessary scaffolding recommended by the PPR has been arranged;
nodes, sections, pipes, fittings, compensators, supports, suspensions and other products are accepted for installation; their completeness, compliance with the requirements of the project and delivery conditions were checked. Industrial installation methods predetermine that components, support structures, supports and suspensions come to the installation site from pipe-producing shops with maximum degree factory readiness and completeness. The completeness of the delivery is checked according to the specifications, packing lists and other shipping documents, and the condition is checked by external inspection. When downloading, it is not allowed to reset pipe blanks and store them in bulk.
By the beginning of the installation of pipelines of sanitary systems, it is necessary to check the performance of general construction work in buildings and structures, including accepting holes and grooves for laying pipelines for installation in compliance with the dimensions given in Table. 61.
When constructing external pipelines for water supply, sewerage, gas pipelines and others, before digging trenches and pits, all underground communications must be opened. Communications are opened with the help of shovels, without the use of percussion instruments. The opening places are fenced off, at night these places are illuminated. The existing communications crossing the pipeline being laid or located parallel to it at a distance that is unacceptable according to the standards are shifted in accordance with the project. Before proceeding with the installation of external pipelines, the route passing
Table 61
Heating
| Riser | yuohyuo | ||
| Two risers |
150H00 | ||
| Connections to devices | yuohyuo |
||
| main riser |
200XY0 | ||
|
Highways | |||
| Plumbing and | sewerage | ||
| One plumbing riser | yuohyuo | ||
| Two water pipes | |||
| One sewer line | |||
| D H57 mm | 150H00 | ||
|
Same, ?>„ 108 mm | |||
| Two water pipes and | |||
| one sewer line | |||
| D K57 mm | |||
|
Same, 108 mm | |||
through locality must be fenced on both sides throughout inventory shields with warning signs. In places of heavy traffic of vehicles and pedestrians, red flags should be installed on the fence.
The laying of pipelines should be preceded by a breakdown of their routes, which is carried out in accordance with the project, where the binding of the pipeline axes to ceilings, walls and columns should be indicated. Axes and marks of pipelines are transferred to the place of laying and the installation sites of supports, fasteners, compensators and fittings are marked.
When laying out the route of intrashop pipelines, the axes and marks are fixed with the help of signs applied directly to the walls of the building, metal and reinforced concrete structures with a scriber or oil paint. The breakdown of rectilinear horizontal axes is carried out first of all, this is done using a steel string with a thickness of 0.2-0.5 mm or a nylon thread, along which the axes of pipelines are applied on structures with indication of vertical marks (taking into account the required slope of the pipeline). The height marks of the horizontal axes of the pipelines are found by measuring from the level of the finished floor with a plumb line and a steel tape measure. If it is not possible to measure from the floor or ceiling, marks from the existing benchmarks (signs of elevation marks set by construction organizations) are transferred to the walls and columns of buildings along the route of the future pipeline every 10 m using a level. From the transferred mark, measure the distance to the axis of the pipeline, which is determined by subtracting the mark of the benchmark from the design distance to the axis of the pipe. A square is applied to the mark of the axis of the pipeline transferred on the column and a horizontal line is drawn with bright paint. The resulting mark is transferred to the next column. If the pipeline will be laid with a slope, then the mark is transferred to the next column, taking into account the direction and slope indicated in the project. Usually, all technological pipelines are laid with a slope towards their possible complete emptying of liquid residues by gravity.
The values of the minimum slope of technological pipelines for various purposes, m, per 1 m of length are as follows:
Gas pipelines and pipelines (in the direction
Break the track first main highway, and then the axis of the branches to devices, machines, fittings or to other lines. Along these axes, the installation sites for compensators, fittings, movable and fixed supports, suspensions, brackets are marked.
When laying uninsulated pipelines in channels, on high and low supports and overpasses, the distance between the walls of the pipes in the light is taken, taking into account the location of the flanges apart, mm not less than: for pipes with?> „, respectively 57 ... 108-80; 108...377-100; over 377-150.
Laying pipelines inside buildings and installations is carried out on supports along walls and columns, on suspensions to floor beams and ceilings, taking into account the free movement of handling equipment. The distance from the floor to the bottom of the pipes or the surface of their thermal insulation must be at least 2.2 m.
The distance between the outer pipeline or the surface of its thermal insulation and the wall must allow free thermal expansion, inspection and repair of the pipeline and fittings, and is assumed to be at least 100 mm in the light. Pipelines laid along the walls of buildings should not cross window and door openings. When laying along the outer walls of buildings, pipelines are located at least 0.5 m above or below window openings.
Upon completion of the laying out of the pipeline route, an act is drawn up, to which a list of axes and turns is attached.
§ 3. INSTALLATION OF SUPPORTS AND SUSPENSIONS
Supports and suspensions are used to fasten horizontal and vertical pipeline lines to buildings, structures and process equipment. According to the purpose and device, the supports are divided into fixed and movable.
Fixed supports rigidly hold the pipe and do not allow it to move relative to the supports and supporting structures. Such supports are perceived vertical loads from the mass of pipelines with the product and horizontal -¦ from temperature deformation of pipelines, hydraulic shocks, vibration, etc. According to the method of attachment to the pipe, fixed supports are welded and clamped. In clamp supports, special stops are welded to the pipe to prevent slipping of the pipe in the support. Fixed supports are manufactured according to the standards of design organizations and manufacturers.
Movable supports support the pipeline, but do not prevent its movement from temperature deformations. They perceive only vertical loads from the mass of the pipeline with the product. They are divided into sliding, roller, frameless and others. Movable supports are manufactured in accordance with GOST 14911-82 * and GOST 14097-77, OST 36-11-75, as well as according to the standards of design organizations and manufacturers.
The pendants are attached to support structures and floors of buildings with the help of rods with bolts or welded eyes. The length of the rods is set by the project and adjusted with nuts or couplings. Pendants are made according to GOST 16127-78, OST 36-12-75.
The installation of supporting structures, supports and hangers is carried out after the laying out of the pipeline route, when the axes are marked and the places for attaching fittings and compensators are determined. Supporting structures are most often attached to reinforced concrete elements of buildings - columns, crossbars, panels, welding them to embedded parts.
After fixing the supporting structures, usually, together with the nodes and blocks of pipelines, the supports and suspensions are mounted in the design position. If it is necessary to pre-fix the pipelines to be mounted on temporary supports and suspensions (in the case of installation of pipelines of complex configuration in cramped conditions, etc.), the latter must correspond in strength to the mass of the pipeline attached to them and be installed on solid structures. After installation of all pipeline units and welding of field joints, permanent supports and hangers must be placed, and temporary ones removed.
When installing supports and supporting structures under pipelines in accordance with SNiP 3.05.05-84, the deviation of their position from the design in terms of the plan should not exceed ± 5 mm for pipelines laid indoors, and ± 10 mm for external pipelines, and the slope should not exceed +0.001 , unless other tolerances are specifically provided for by the project. To equalize elevations and ensure the design slope of pipelines under the soles of the supports, it is allowed to install steel gaskets and weld them to embedded parts or supporting structures.
The change in the length of the suspension rods is made due to the thread on them.
Welded joints of pipelines should be at a distance of no more than 50 mm from the supports, and in steam and hot water pipelines controlled by the USSR Gosgortekhnadzor - at least 200 mm. Flange connections of pipelines are recommended to be placed, if possible, directly at the supports.
Fixed supports are welded to the supporting structures and securely fixed to the pipe using clamps with locknuts installed on the bolts. The pillow and the clamp of the support are pressed tightly against the pipe. In order to avoid shearing of the pipe in a fixed support, thrust plates are welded to the pipe, which should rest against the ends of the clamps. The stops are set so that the gap between the clamp is no more than 1.5 mm. The surface of the stops and the surface of the pipe at the installation points must be cleaned with a manual grinder before welding. Thin aluminum spacers are installed between the alloy steel pipe and the carbon steel support or clamp to protect the contact points from electrochemical corrosion.
Movable supports and their parts should be installed taking into account the thermal change in the length of each section of the pipeline, for which the supports and their parts must be displaced from the axis of the supporting surface in the direction opposite to the elongation of the pipeline. The displacement value is usually taken according to the project as equal from the base to the full thermal elongation of a given section of the pipeline. Pipe hanger rods with thermal elongation must be installed with an inclination to the side. The amount of displacement and the direction of the preliminary inclination of the rods are specified in the project.
§ 4. INSTALLATION OF PIPING
With industrial methods of conducting work, installation of tr ^. pipelines are performed by nodes, sections and blocks. At present, the installation of aggregated blocks has become widespread, i.e. pipeline blocks are assembled together with technological equipment and install them on a common frame.
Enlargement assembly of blocks is carried out on stands and racks located in the area of operation of assembly cranes. Here it is advisable to use stands 21338 (see Fig. 10) and centralizers (Fig. 46). Before assembling the blocks, temporary plugs are removed from the fittings and assemblies and the flanges and pipe ends are re-opened. After control measurements of the finished units and checking the location of the fittings at the equipment, assembly of the blocks begins. The dimensions and weight of the blocks should ensure the convenience of their transportation to the installation site and installation in the design position. Knots and blocks must remain strong during lifting, otherwise they may be deformed. If necessary, temporary structures should be installed to provide the required rigidity.
Rice. 46. Pipe welding centralizer TsT-426:
1 - screw;2 - screw; 3 - cheek;4 - link; 5 - roller;6 - straightening
vnnty
Straight sections are laid after installation and fixing of adjacent nodes and blocks. It is advisable to mount supports and suspensions on the units and blocks being lifted, this facilitates the subsequent alignment. When installed in the design position, units and blocks, as well as sections and individual pipes, must be laid on at least two supports and securely fixed. Temporary fastening of pipelines for the period of installation is allowed in exceptional cases. Pipelines laid through walls, ceilings or other elements of buildings must be enclosed in sleeves in accordance with the design instructions. In the absence of instructions, it is recommended to use pipe sections with an inner diameter 10-20 mm larger than the outer diameter of the pipeline section enclosed in them as sleeves. The sockets should protrude 50-100 mm on both sides of the building element intersected by the pipeline. Sections of pipelines in sleeves should not have joints. The gap between the pipeline and the sleeve is filled on both sides with asbestos or other non-combustible materials that allow the pipeline to move in the sleeve.
Lifting and installation of nodes and blocks in the design position are carried out with the help of cranes, rigging equipment and devices provided for by the PPR. Hoists, blocks and other rigging used in the installation of pipelines may be attached to the nodes of building structures that have the necessary margin of safety. In the absence of relevant instructions in the PPR, the possibility of fastening to building structures must be agreed with the design organization.
Pipe fittings are installed, as a rule, complete with nodes or blocks. When installing fittings that are not included in the units or blocks, they are preliminarily fixed on supports, after which the pipeline is attached to it.
It is expedient to carry out installation of external elevated pipelines by the enlarged blocks and sections. The dimensions and designs of blocks or sections are determined in the PPR and depend on the structures of the overpasses, the number and location of pipelines on the overpasses, their diameters, whether the installation organization has lifting mechanisms, as well as installation conditions. Enlargement assembly of blocks and sections is carried out on stationary or mobile lines. Sections are lifted onto supports or overpasses, usually with the help of two cranes, the types of which must be indicated in the PPR.
Installation of underground pipelines is carried out in the following sequence: trenches are developed; clean the bottom and walls of trenches; dig pits in places of welding and insulation of joints; arrange a foundation for the pipeline; perform the bottoms of wells and chambers; lower pipes into trenches, laying them on the base; assemble and weld closing joints; install connecting parts and fittings, knock out and sprinkle the pipeline with soil (except for joints); purge the pipeline with air; pre-test the pipeline for strength; isolate joints; fill up the pipeline. The final test of the pipeline is carried out after the completion of construction and installation works.
Centralizers are used to center the ends of pipes assembled for welding and to eliminate misalignment of edges along the perimeter of pipes. The pipe welding centralizer TsT-426 is a spherical-link plate chain assembled from links mounted on free-rotating rollers with threaded holes into which fixing screws are screwed. The right extreme link is made in the form of two lamellar hooks closing the centralizer and pins of a nut having a right-hand thread. To tighten the centralizer and joined pipes, a screw is used, located parallel to the tangent to the pipe circumference. The screw has right and left thrust threads. The rotation of the screw is recommended to be carried out using a ratchet wrench with adjustable torque with an interchangeable head with a 14 mm opening.
To center the pipes during their assembly, it is necessary to lay the centralizer so that both rows of plates are located symmetrically to the pipe joint, then the hooks are put on the trunnions of the right nut and the centralizer is tightened by turning the screw until the axes of the pipes to be joined are aligned. Where it is necessary to eliminate the offset of the edges, fixative screws are screwed into the threaded holes of the rollers. In this case, the torque must not exceed 30 Nm.
When changing the diameter of the assembled pipes, the number of links of the centralizer is changed.
Technical characteristics of the centralizer TsT-426
Outer diameter of joined pipes,
mm..........219-426
Maximum tightening torque, Nm:
Manufacturer ....... Poltava experienced
foundry and mechanical plant Minmontazh- spetsstroy of the Ukrainian SSR
Pipelines laid in trenches are recommended to be installed in sections and lashes up to 1000 m long. At the same time, ready-made coded pipes or sections 24-36 mm long are laid out at the edge of the trench, their joints are assembled and welded in a fixed position. The assembly of the lashes is carried out on the bars-beds or on the excavated soil for the convenience of their subsequent slinging when laying in a trench. Between the sunbeds, a distance of up to 35 m should be provided, the bottom of the trench should be planned taking into account the design slope. In order not to damage the insulation, the pipeline is lifted with the help of special slinging devices - towels, consisting of a steel rope and an inner protective sheath made of rubberized fabric. Laying the lash in the trench is recommended to be carried out using three cranes located along the lash at a distance of 15-40 m from each other, depending on the diameter of the pipelines.
Only specialists in this field have the right to carry out work on the installation of a gas pipeline. To provide gas to a private house or to repair gas communications, it is necessary to choose professionals.
Installation of pipes is carried out in accordance with the norms of SNiP 2.04.08–87. This document regulates all actions, distances and sizes of mounted communications.
The gas pipeline is one of the most important parts of the house. Thanks to him, heating appears in the room, with the help of gas appliances you can cook food and heat water for domestic hot water. But if used incorrectly, gas can become a serious problem leading to tragedy. To avoid this, the standards used in the installation of the gas pipeline were invented. They ensure the safety and correct operation of the devices.
Basic Rules:
- It is not allowed to cross the gas pipeline and window openings, doors and ventilation.
- Distance from pipe to electrical panel should be at least half a meter.
- Between gas system and electrical communications should be at least 25 cm.
- The gas pipeline should be at a height of 220 mm from the floor, in rooms with a sloping ceiling this distance is 200 mm.
- Can be connected to gas appliances flexible hose 10 mm in diameter.
- Water heaters cannot be installed in the bathroom.
- High humidity creates reverse thrust, due to which the room is filled carbon monoxide and may cause poisoning.
- The distance between the plate and the pipe must be maintained, it must exceed 80 cm.
- After metering devices, a pipe slope of 3% should begin.
- The metering device should be located at a height of 1600 mm from the floor.
- The counter should be located at a distance of 80 cm from heating equipment or slabs.
- To install the gas pipeline in the wall, it is necessary to make a hole in the wall separate from the ventilation.
- It is necessary to provide access to communications. You can put them in a box, but it must be equipped with a lid for access.
Preparatory work
Before starting the installation, it is necessary to prepare the site. To do this, you will have to coordinate the work with the relevant organization. Coordination of the installation of the gas pipeline is carried out in the following order:
- Write an application to the company that monitors the gas economy.
- The specialist will issue a verdict on the possibility of carrying out certain works.
- If the work is allowed, the specialist will draw up an estimate for their implementation.
Permits for the installation of a gas pipeline are issued in accordance with SNiP 2.04.08–87 and the “Safety Rules in gas industry". Preparation, coordination and drafting of the project make up a significant part of the costs.
Used equipment and tools for installation
For the installation of the gas pipeline, the masters use special equipment:
- Long-staple flax or FUM-tape for threaded connections.
- Lever wrenches with parallel jaws. They should be equipped with notches for better adhesion to the part.
- Apparatus for welding.
- Fittings - parts with fine threads for connecting several elements.
All tools and elements of the system must have a certificate from the factory that manufactures these parts. All certificates must comply with the requirements of Gosgortekhnadzor. If there are no certificates, then the use of such pipes is impossible.
Procedure
Installation of the gas pipeline begins with measurements of all required dimensions. Based on the data obtained, specialists draw up a project for the future gas network.
After agreement, it is necessary to order the manufacture of the parts necessary for the project, buy expendable materials and deliver it all to the assembly site.
When all parts of the structure are ready and delivered to construction site you can get straight to work. When laying pipes, it will not be possible to use gas equipment, so you have to worry in advance alternative method heating or cooking at the time of work.
Gas pipeline installation technique
Work begins with the introduction of pipes into the building. For this in outer wall the case is placed and input is performed through it. Already inside, a riser is fixed, located 20 mm from the walls in a vertical position. Connections at this stage are made using a welding machine.
Cases should be located in all places where the pipe intersects with interfloor ceilings, walls and stairwells.
Gas pipe fittings must be installed at least 2 m apart. These rules apply to pipes with a diameter of 25 mm. They should allow for the repair and diagnosis of possible damage during operation. The end of each of the fasteners is hammered into a special wooden plug located in the wall. After that, the attachment point is poured cement mortar to give extra strength.
There are a number of rules for performing welding work:
Welding rules
- Welding can be performed on pipes with a diameter not exceeding 150 mm and with a wall thickness of up to 5 mm.
- Arc welding is used when the pipe thickness exceeds 150 mm or the wall thickness exceeds 5 mm.
- Before installation, it is necessary to prepare pipes for welding. To do this, they are cleaned of contaminants.
- To everyone welded joint easy access must be provided. Hiding seams in the wall or case is not allowed.
It is important to note that the presence free access mandatory for all joints, not just welds.
All connections are made by welding. Threaded connections are allowed only at the places of installation of stop valves, metering devices (gas meters), connection of a pipe with a hose leading directly to gas equipment.
Question #6: Hello. Exist typical series or attached to the fastening of a vertical gas pipeline to a ventilated facade? Thank you in advance. (Valentina Yurievna Answer: Today, in the construction markets, you can buy hardware and fasteners for every taste, both domestic and foreign manufacturers. One of these products is a collapsible fastening clamp (see photo). Designed specifically for attaching to the walls of the supporting structures of pipes of gas pipelines, sewerage, heating and water supply.
It consists of two metal brackets, one of which is welded with an M8 nut, rubber gaskets are installed in the brackets, and two screws are used to tighten the clamp. To attach the clamp to the wall, use either a stud with a dowel or anchor bolt.
Fastening to the wall through the already installed siding is carried out as follows, directly through the siding, insulation, we drill a hole in the wall for a dowel or anchor bolt, screw the stud into the dowel or bolt with the body into the prepared hole, and wind the half of the collapsible clamp onto the second end of the stud or bolt. Everything, the mount is ready for operation.
Such collapsible clamps today are indispensable for the repair and arrangement of heating systems, water supply and gas supply, and of course sewerage. Clamps are of high quality and meet the highest requirements, are made of high quality steel by cold stamping, galvanized zinc coating, standard size is represented by a wide range: 1/2", 3/4", 1", 1 1/4", 1 1/2", 2", 2 1/2", 3", 3 1/2", 4", 5", 6".
All sets of collapsible clamps are equipped with rubber gaskets that protect the metal of the clamps from corrosion when in contact with the working pipe, and are also sound and vibration dampers.
The nut is welded to each clamp using resistance welding, this ensures high reliability of the welded assembly during pipe fastening and installation. Such a connection can withstand a nominal load within 150 kg, the pull-off force is guaranteed in the amount of 450 kg.
I think depending on the material bearing walls you choose the type of fastening yourself: either a stud with a dowel or an anchor bolt. If the walls are generally made of gas blocks, then you can use chemical anchors. A hole is also drilled through the siding and insulation, a special mixture is pumped into the hole and then an anchor bolt is inserted, chemical reaction, the substance polymerizes and the anchor bolt is firmly fixed in the wall of the house. And then according to the scheme above: we fasten the collapsible clamp with rubber gasket. Good luck.
