Powder fire extinguishing modules - principle of operation and triggering conditions. Powder fire extinguishing - system features, principle of operation and classification Principle of powder fire extinguishing

Powder automatic plants modular type have a slower response than carbon dioxide, contaminate and damage surfaces, and do not fill space as effectively as gas, but are cheaper, safer, more versatile, with less need for room sealing.

For a powder extinguishing composition (OP), the form of a fire extinguisher in the form of a module is the best option, since it is difficult to move the mixture through pipes as in centralized fire extinguishing systems (gas, water, air-foam). But this does not exclude the use of MPP with a small wiring with inlet pipes and sprayers.

The device and principle of operation of the powder module

MPP - an independent element automatic installations fire extinguishing (AUP or AUPP). The module is triggered and releases fire extinguishers at the fire site after receiving an actuating impulse.

The difference between the options for the execution of AFS and the supply of extinguishing agent:

The composition of the fire extinguishing powder (GOST R 53280.4, NPB 170-98):

1. phosphorus-ammonium and other mineral salts;
2. displacing gas: compressed air, nitrogen, helium, argon;
3. against clumping: white soot, graphite.

MPP has a double effect: it extinguishes with powder and gas. Action OTV:

1. cold mixture removes (inhibits) excess heat from the hearth;
2. the burning surface is adsorbed, becomes non-combustible;
3. the powder creates a coating that prevents combustion;
4. oxygen is displaced from the fire;
5. the suspended cloud acts as a fire barrier;
6. the powder decomposes, substances are released for self-extinguishing;
7. pressure knocks out the flame.

Modules powder fire extinguishing by operation type:

• autonomous - the whole system: sensors, alarms, stimulator - on the cylinder. MPP is a self-sufficient device;
• automatic with central activation- sensors send data to a single console (control unit), from where the impulse comes to the ZPU;
• manual (remote or local) start- are activated manually by the operator from a remote location by means of a duplicated start.

Ways to eliminate the fire:

1. surface quenching- spreading of OP to the surface to cover the flame;
2. volumetric - the entire space of the object is filled with a mixture;
3. local - spraying to a certain point, area (on an electrical panel, motor).

MPP design

An automatic powder fire extinguisher is located at the epicenter or in close proximity to a possible source of fire.

The purpose of the WFP is to eliminate the fire without human intervention. Products for hazardous areas are equipped with a protected housing. A modular powder fire extinguishing system can include several containers.

MPP options:

1. by security:
   • general (from -50 to + 50°C);
   • heat resistant (-60 to +125°C) plus vibration resistant;
   • explosion-proof;
2. on placement: floor, ceiling, wall execution.

General execution

Elements of the MPP:

1. capacity: cylinder (Buran-2.0), sphere, oval, ceiling (Buran-2.5). Options:
   • inside: OP, initiating node with fuse and explosive charge connected to sensors;
   • cylinder with a stimulator of 2 segments (chambers, containers). In one - an extinguishing composition, in the other (from below) - a gas-generating substance;
2. inside a siphon tube with holes for loosening the OP;
3. locking and starting device with a self-launching unit (incentive part) with a nipple, membrane, seal;
4. safety valve;
5. sensors, temperature sensitive element;
6. detectors, annunciators;
7. small wiring with supply sleeves (less often);
8. sprayers;
9. thermal heating element, pyrocharge;
10. electrocontact group;
11. thermal jacket.

Explosion-proof version

Explosion-proof powder modules are used to extinguish fires in rooms with explosion hazard class A and B, mines, mines (and zones).

The body of the MPP (Buran-8vzr) is thicker, with protective covers, heat-resistant elements.

Time (duration) of the module

MPP according to the duration of the jet release, actions:

1. fast (impulse action) - up to 1 sec. (AND);
2. short-term 1 - 15 and more than 15 sec. (KD-1 and 2).

Response time (inertia) – from 1 to 30 sec. (B1 - B4).

MPP service life

According to the standards (GOST 53286-2009) service life:

1. rechargeable - from 10 years. In practice, in standby standby mode, subject to regular maintenance, the module lasts 15 years or more;
2. non-rechargeable- period in TD.

The established indicator of the probability of functioning without failures is from 0.95.

Types of MPP powder modules

Varieties in design and operation:

1. OTV release and extinguishing method:
   • pumping (Z);
   • with a pyrocharge and a gas generating part in a separate chamber (GE, PE) or in a cylinder outside (MPP-100-07);
   • with a separate pressure source capsule (PSG);
2. frame:
   • self-destructive;
   • indestructible;
3. by way of placement:
   • ceiling, wall (high-rise, medium-rise);
   • floor.

Fire extinguishing modules with powdered extinguishing agent are triggered by temperature or pressure changes in the room. The impulse comes from the control unit or from the alarm.

Electrical

Electric start with a self-destructive case:

1. The pulse of the sensor or alarm goes to the stimulator (electric activator).
2. The gas generating charge is started.
3. The pressure in the chamber increases.
4. The membrane is destroyed, gases fill the segment with OP through the perforation.
5. The extinguishing agent is loosened, saturated with gases, and brought into a fluidized state.
6. The pressure inside the case is rising.
7. The balloon opens along the notches.
8. The powder is ejected at high speed onto the hearth with a hemispherical torch. Escaping jets empty the container at different positions.
9. After the mixture is ejected by 95 - 97%, an inert gas escapes behind it, improving extinguishing.

self-triggered

MPP, activated independently (Buran-2.5), with thermochemical start:

1. When a fire occurs, the temperature rises.
2. The case gets hot.
3. The temperature is transferred inside the powders: extinguishing and initiating (at the bottom of the module).
4. Upon reaching a critical level (+85°C - +90°C), the initiating composition starts a chemical reaction.
5. The temperature inside the cylinder rises to +300, +400°C.
6. Fire cord ignites.
7. The thermal impulse for starting is supplied to the gas generating charge. Further stages are similar to electric start.

In self-triggering MPPs, everything is tied to natural processes chemical substances and pressure. If the body is one-piece, then the extinguishing agent is ejected, passing through the siphon tube to the sprayer.

Another option is cable. Principle of operation:

1. The temperature reaches the set level.
2. The flask is destroyed.
3. The castle is divided into two parts.
4. The cargo is released.
5. Ballast on a steel cable moves, the installation starts.

Mechanical

Powder modules with mechanical (forced) activation are used where it is inappropriate to use an electrical system. Examples:

1. drying and dyeing chambers;
2. objects with high dust content.

Mechanical start: the operator actuates the chain of levers or turns the clamp (faucet). The ZPU rod pierces the membrane or activates the gas generator, releasing the OP onto the fire (MPP-100-07).

Combined

An example of a combined starting unit: MPP BURAN-2.5-2S with a thermal self-start unit and an electrical circuit. It is activated both by an alarm pulse and by temperature, which allows the module to be used both as a stand-alone module and in a centralized fire extinguishing system.

Most automatic powder fire extinguishers of modular type are equipped with an additional manual start, actuated by a squib or combined starter.

Rules for placement of MPP modules

To obtain a fire safety certificate for the premises, installation is carried out by masters of specialized licensed enterprises. Specialists create technical plan, substantiation, installation design, graphic designation of the scheme.

Calculation of the number of modules

The calculation should proceed from the need for uniform processing of the protected area. The calculation depends on the number of OP. The tables are listed in GOST R 53286-2009 (clause 5.14). Examples:

MPP manufacturer in technical documentation may indicate the fire-extinguishing capacity of the product (sq. m / fire class), but for accurate calculation there is a technique that takes into account specific values, installation standards:

1. type of object by danger;
2. humidity;
3. diagrams, spray uniformity.

Rules for determining the number of MPP contains App. 1 "General provisions for the calculation of modular type powder fire extinguishing installations", Section 9 of SP 5.13130.2009.

Where should be placed

MPP (AUPP) are intended for places where:

1. it is impossible to detect and extinguish a fire by conventional means;
2. fires A - D, electrical installations up to 5000 V;
3. there are no alternatives to fire extinguishing powder for alkali metals and chemical warehouses.

Pollution of the MPP of the object is conditional - the OP is removed with a brush, vacuum cleaner, but the OP particles can be fused with the braid, metals. If the substance is not removed quickly, corrosion will occur on the materials, therefore, MPP is recommended by the NPB if there are no more gentle alternatives. Often there are none, since powder formulations are the most versatile and cheapest.

Conditions for object and installation:

1. cases, nozzles are fixed in protected areas according to TD;
2. take into account the temperature regime of the area;
3. containers with a pipeline are placed in a special enclosure, box;
4. brackets must support a load 5 times greater than the weight of the module;
5. it is allowed to install nozzles and sprayers in a cascade;
6. leaks of 1.5% are allowed if volumetric quenching occurs;
7. the room must be airtight according to the TD, without voids and cracks, without unreasonable openings, self-opening doors. With a hole area of ​​15% or more, only surface or local quenching is used;
8. before fixing, the MPP is sharply turned to the sides to evenly distribute the OP inside;
9. enterprises are equipped with a sign “EXIT”, “POWDER! LEAVE";
10. installation in large spaces is done with zoning;
11. staff are instructed. An evacuation plan is being developed: people must leave the building before the AUPT is triggered.

Do not extinguish MPP:

1. materials;
   • pyrophoric;
   • smoldering and burning without air;
   • self-igniting and smoldering inside (sawdust, cotton);
2. objects, areas:
   • with the impossibility of evacuation before the start of extinguishing, with a staff of more than 50 people, except for specially designed fire extinguishing schemes ();
   • outdoors, in open areas;
   • in warehouses of products in aerosol packages, inside mobile racks.

Examples of facilities for accommodating WFP:

1. warehouses, sheds, closets (fuel and lubricants, fuel);
2. industrial zones;
3. fuel, mining, paint and varnish enterprises;
4. garages;
5. with electrical equipment (up to 5000 V), wiring (automatic telephone exchange), but taking into account the possibility of corrosion and powder fusing into metals, plastics;
6. they are less commonly used in libraries, archives, for warehouses of medicines, food, as they contaminate materials.

Powder Module Maintenance

Maintenance consists of checks, surveys, inspections, cleaning, replacement of unusable parts (, "On the fire regime").

THEN :

1. monthly:
   • inspection;
   • cleaning;
   • checking electrical parts, grounding;
   • power control;
   • health check;
2. grounding resistance is checked annually;
3. once every 5 years, a complete examination and recharge.

How to test a module

Fire extinguishing modules with a powder composition must serve filling stations and specialized licensed organizations. If the MPP is activated during the maintenance process, then replacement, refueling will be required, so only specialists check the performance.

Reloading modules

Refueling is done:

1. after each actuation;
2. refueling - if it is provided by the TD;
3. the mandatory recharge period is once every 5 years.

Standards for storage and disposal of MPP

MPP is stored in conditions that protect the device from mechanical influences, heating, climate influences and aggressive environments(). Utilization of modules is carried out by service specialized organizations for fire safety.

For security in the premises, various systems are installed. Powder fire extinguishing allows you to quickly and efficiently eliminate the fire. At the same time, the system has its own characteristics of work, pluses and minuses.

How fire is extinguished

Now many options are used to extinguish a fire when water is powerless. This is due to several reasons:

1. Many flammable liquids are less dense than water. They wrap the surface of the water with a film, so the scale of the fire becomes larger.
2. Pouring water on chemical components, electrical equipment is dangerous. Fighting the fire will be difficult.
3. Extinguishing with water is not effective in every room, for example, in a room with equipment, books, paintings. because of water element what the fire could not cope with will be eliminated.

Anhydrous options

Anhydrous methods allow to reduce losses and improve the efficiency of fire extinguishing. These include:

1. foam systems.
2. Gas installations.
3. aerosol methods.
4. Powder fire extinguishing.

This diversity allows you to choose the most suitable option for each room.

Powder Method

To eliminate the fire, it is necessary to close the supply of oxygen to the hearth. Powder fire extinguishing perfectly fulfills this task, since the mixture has the properties of metal salts.

The extinguishing procedure is carried out as follows:

1. Upon contact with burning surfaces, the powder is heated, due to which the combustion temperature decreases, since a lot of heat is spent on heating the powder.
2. The mixture starts to work. With the decomposition of metal salts, gases are formed that do not support fire. An air-powder suspension appears near the place of combustion. Because of it, the supply of oxygen stops, which reduces the intensity of the fire.
3. Powders contain flame retardants.

Automatic powder fire extinguishing can be used to eliminate fires of different classes, no matter what the characteristics of hot substances and objects may be.

pros

Powder fire extinguishing has the following advantages:

1. Cheap option.
2. Easy system installation.
3. Durability.
4. Suitable for different materials and items.
5. Versatility.
6. Large range of use.
7. Safety.

Classification

An automatic powder fire extinguishing system is usually used in non-residential premises where it is undesirable to use water. Such objects include archives, libraries, paper warehouses, museums, chemical enterprises, automatic telephone exchanges, equipment rooms.

Powder systems are divided into:

1. Centralized. The extinguishing agent is supplied from one tank.
2. Modular. It is submitted in modules in the territories of use. The powder fire extinguishing module consists of everything you need to spray a fire extinguishing component using a remote control.

The powder is ejected by high pressure gas. Systems are classified according to several criteria.

By module design:

• Gas generation is carried out when triggered due to the gas generating substance.
• The gas is preloaded.

By quenching method:

• Volumetric - enough for the whole room.
• Surface - the mixture is distributed over surfaces.
• Local - the powder is applied to some parts.

Hazardous substances are used to produce fire extinguishing powders, so the premises where these systems are equipped must include means of audible danger notification. There may also be light displays “POWDER! DO NOT ENTER!"

When the powder is not applied

Powder extinguishing systems are effective, but not ideal. They cannot be used in some cases:

1. Extinguishing components that can burn in an oxygen-free environment, smoldering materials.
2. From the metal, the powder must be removed immediately, since metal salts act quickly, which can lead to the destruction of products.
3. The powder is difficult to convey through pipelines. Because of this, it is not easy to use in systems with a centralized supply of material for extinguishing fires.
4. Powders have a negative effect on humans, so they can be used in areas where there are no people.
5. It can not be installed in objects with a huge crowd of people. Turning on the systems can be life threatening.

Automation

Extinguish immediately after fire. Then the fire is quickly localized, and losses are minimized. Automatic settings reduce the time from ignition to mixing. AT industrial premises and in warehouses where combustible, explosive, chemical components are present, automation is necessary.

Automatic systems perform many functions:

• Notifying people of a fire.
• Fire localization.
• Preservation of the strength of the building, equipment.

The command to extinguish the fire is given automatically or manually from the place of management. because of physical properties powder it is difficult to use in centralized systems. Many operating systems are modular in design.

Mounting Features

System installation is carried out in the following steps:

1. System design after inspection of the premises. The project should be created in such a way that it fits the standards of GOST, SNiP. It will also be coordinated with the Ministry of Emergency Situations.
2. Formulation of the budget. The price of installation is determined by the architectural and planning features of the premises.
3. Installation.
4. Start-up and adjustment activities.

The number of modules is set on the basis of SP 5.13130.2009. The calculation is performed by 4 methods:

1. Area based.
2. Locally.
3. By volume.
4. By cubature.

A suitable option is established on the basis of the characteristics of the room and the place of ignition. For example, in objects without shaded areas with a ceiling height equal to the powder spray height of the module, a simple calculation is performed. The area of ​​the room must be divided by the area protected by 1 installation. The indicator is recorded in the data sheet of the module. Local protection is necessary in those facilities where there is a large area, and there are few fire hazardous areas.

During the design, take into account the height of the ceilings and the load on structural details to which the system will be installed. During the operation of the module, the load on the ceiling product increases by 5 times. The load is maintained for 0.2 s. Resistance to an actively increased load is taken into account during the calculation of the fire extinguishing system in those facilities where dropped ceilings. Their height must be optimal indicator spraying, indicated in the passport.

False positives

Spraying of the substance occurs after the sensors are triggered or on the basis of a signal provided from the central console. Own sensors increase efficiency, but may function falsely. This is due to several reasons:

1. Work failures.
2. Human factor.
3. Electromagnetic pickups.
4. Startup correct.
5. Battery discharge.

Best Modules

Security is provided by many systems. But the most popular include the following:

• Powder fire extinguishing module "Buran - 1.5 - 2 s.". It has a double triggering function - from an external signal and its own sensors. It is used as an independent tool or part of the system. The body is presented in the form of an oblate shape, which is suitable for administrative premises, entertainment facilities, shops. The module allows you to eliminate any fire. Continuously running 0.5s. The cost of equipment is about 1300 rubles.
• "Buran-8vzr" is explosion-proof. Used in buildings where high class explosiveness. Allows you to protect a large area. It is created in the form of a universal system and wall. The price is about 4800 rubles.
• Powder fire extinguishing module (MPP "Tungus"). Created in several forms. Works at temperatures from -50 to +50 degrees. Special systems operate in the range of 60-90 degrees. Can be used to extinguish any fire. Price - 7400 rubles.
• "Tunguska". It is used to quickly extinguish a fire. It can be used in hard-to-reach areas that are difficult for cars to access. It is applied on fire hazardous objects. There are 9/18 modules in the installation.
• "Impulse-6", "Impulse-6-1". Suitable for extinguishing any fire at temperatures from -50 to +50. It is used in production, household premises, warehouses. The mixture is supplied by a gas generator. Operation occurs from an electrical impulse. Gas removal occurs after operation inside the case. The mixture is produced under pressure.

Spray Elimination

The powder is simply removed by dry cleaning. Residues can be removed with a vacuum cleaner. A water filter or respirator is also needed. Cleaning of the Buran system is carried out by washing and wiping, if the mixture is on varnished surfaces.

If the powder has expired, it must be disposed of in a sealed bag. It can be thrown away or used as fertilizer for crops. In this situation, yields are increased and the risk of plant damage by pests is reduced.

Powder replacement is carried out in specialized companies that have received a license for their work. But it is advisable to purchase new models, since it will be more efficient and safer.

Powder fire extinguishing is included in the system fire safety buildings, structures, sometimes individual devices and units. This type of fire extinguishing is used to extinguish fires where it is impossible to extinguish with water, foam or water mist.

These are areas where extinguishing with water can lead to an even stronger fire:

• production of certain chemicals;
• electrical equipment under voltage;
• premises for the storage of flammable liquids.

It also includes premises with the storage of large material values ​​​​and works of art, where extinguishing with water can cause even more damage than the fire itself.

The scope and rules for installing powder fire extinguishing systems are enshrined in the following regulatory documents:

• set of rules "Fire protection systems", norms and rules for designing SP 5.13130.2009;
• fire safety standards NPB 88-2001;
• guidance documents RD 25.952-90;
• fire safety standards NPB 110-03 and others.

The current Rules and Regulations are absolutely binding. Sometimes it seems that they include superfluous, unnecessary requirements. But as the veterans of the fire service say, they are all written in blood.

Powder fire extinguishing is used for fires of class A, B, C. For explosive premises, when using the system, additional measures security.

Powder systems must not be used in areas that people cannot leave before the fire extinguishing agent is sprayed, as well as where a large number of people can stay.

The powder fire extinguishing system has certain advantages. This is first of all:

• the relative cheapness of the system, in its field of application, powder fire extinguishing systems are the cheapest;
• ease of installation and convenience of design;
• the possibility of long-term storage of the powder, which is good for use both in systems and in fire extinguishers;
• universality, the powder can be used both in extinguishing ordinary fires and in specific fires of metals, chemicals, electrical equipment;
• rooms where the powder system is used do not need to be sealed - gas fire extinguishing requires mandatory sealing;
• wide temperature operating conditions from -50С to +50С, which allows using the system in unheated premises.

When extinguishing a fire with powder, energy is spent on heating and evaporating powder particles, which leads to a slowdown in oxidative reactions and cooling of burning surfaces. When the powder decomposes, gases arise that impede the access of oxygen to the combustion site, which speeds up the extinguishing of the fire.

disadvantages powder method extinguishing fires are:

• poor result when extinguishing substances that continue to burn without access to air or smolder in the depth of the layer ( sawdust);
• to avoid damage to the equipment, the mixture must be removed from all surfaces as soon as possible;
• powder is worse transmitted through pipelines than liquid and gas;
• extinguishing mixtures are toxic and pose a risk to human health.

There are two types of powder fire extinguishing systems. It is a centralized and modular system. In centralized systems, the powder is supplied from a central reservoir, while in modular systems, the extinguishing agent is contained in each module.

The module contains everything you need to spray the powder on command from the central console. The powder is ejected under high gas pressure.

As automatic fire extinguishing systems, mainly modular systems are used, since with a centralized supply of powder there are significant engineering difficulties in creating pipelines.

These systems are divided according to the method of distribution of the powder in the premises into:

• voluminous;
• superficial;
• local.

In volumetric systems, the powder is distributed throughout the volume of the room; in the surface - along the walls, floor and ceiling; in local - directly on the surface of the protected object.

POWDER FIRE EXTINGUISHING MODULES

The powder fire extinguishing module is the main element of the system. Its design provides for the storage of a fire extinguishing agent and the possibility of operation. The numbers in the module marking indicate the case type, capacity, operation time, method of gas storage in the case, climatic version.

By design, the modules differ in the way they produce gas. Gas is either pumped into the module in advance or generated at the time of operation.

Among the most commonly used modules are Buran and Tungus. Both of these modules are available with a gas generating element.

Fire extinguishing module "Buran" has a spherical body with flanges. Inside the case there is a powder and a gas generating element with a launcher. Buran can operate both as part of a fire safety system and autonomously.

Models in the series of modules "Buran" differ in the amount of fire extinguishing powder, in response time, in continuous action time. Modules are produced for rooms with different ceiling heights, different volumes. Modules "Buran" are produced with ceiling and wall system mounts. Explosion-proof modules have a special design.

For example, the MPP(r)-8SV-I-GE-UHL "BURAN-8SV" module, where: MPP (r) - powder fire extinguishing module (with a partially destructible body); 8CB - volume 8 liters, medium height; And - impulse action; GE - with a gas generating element. Buran modules are mainly used in warehouses, commercial premises, fuel and lubricants enterprises, automotive enterprises and power plants.

Powder fire extinguishing module "Tungus" it can also be produced with an electronic trigger unit, when using which it can work autonomously. Modules "Tungus" also have different amount powder. The response time and the continuous operation time depend on the device type. The possibility of wall and ceiling mounting is provided.

A feature of the Tungus modules is the absence of pressure inside the housing during passive operation. The pressure inside the housing is only generated during actuation. This makes the device more durable.

White soot is used as an additional filler in the Tungus module, which reduces humidity and avoids sticking of materials and preserves equipment as much as possible.

Tungus modules are used in cultural and civil facilities, schools, hospitals, data centers, as well as oil, gas and mining enterprises.

The amount of powder in the Buran modules varies from 0.8 to 50 kg. The Tungus modules contain from 0.65 to 24 kg of fire extinguishing agent.

INSTALLATION OF POWDER SYSTEMS

It is possible to proceed with the installation of the system only if there is a well-executed project. When designing, the main technical solutions are determined depending on the type of object, production technology. The project must carry out the necessary calculations, on the basis of which the types of equipment are selected.

The project must take into account architectural features premises and climatic conditions. The arrangement of equipment and the routes for laying control cables are displayed on the drawings. Mounting and commissioning works must be produced in accordance with NPB 56-96.

The installation organization must have a certificate (license) to perform this type of work.

Before starting work, it is necessary to check the construction readiness of the premises. When installing the equipment, it is necessary to be guided by the passports and technical specifications for the products. After installation is completed, it is necessary to carry out commissioning and individual testing of the system. Tests are also carried out during the comprehensive testing of all fire prevention measures. All insulation measurements and tests of squib cartridges are documented in protocols.

When installing the system, it is very important to provide for integration into the overall security complex of the building. This means that when the system is triggered, a whole range of actions should start:

• the elevators of the building (if any) should go down;
• smoke shafts open;
• ventilation is turned off;
• the air boost system is turned on;
• the fire alarm system is activated;
• doors on escape routes open (in case they are closed by the access control system).

The room where there is powder fire extinguishing must be equipped with light panels "Powder - do not enter!" This board is located outside the protected premises. Placard "Powder - go away!" is located indoors. These boards can be equipped with a sound signal. The scoreboard inside turns on at least 15 seconds before the system is triggered.

In the fire extinguishing system, as well as, however, in other fire fighting systems, the problem of false alarms is very relevant.

Powerful systems are launched that not only run idle and create panic, but also consume a large number of electricity. At the design stage, the system is expected to be triggered by at least two sensors.

And during the operation of the system, it is necessary to strictly follow the technical regulations for servicing all components of the system, in particular, wipe the dust from the sensors. Dust causes false positives.

* * *

© 2014-2019 All rights reserved.
The site materials are for informational purposes only and cannot be used as guidelines and normative documents.

* MODULAR * INSTALLATION AND MAINTENANCE *

Each of the existing automatic fire extinguishing systems has its own advantages and disadvantages. In addition, when choosing the type of fire extinguishing installation, one should take into account the features of its application, which is determined by:

• fire class;
• features of the object (premises) to be equipped with a fire extinguishing system.

In addition, as a rule, the cost of equipment and its installation is also an important factor for the customer. It is from these positions that automatic powder fire extinguishing is the most preferable option. Of course, subject to compliance with the regulations that determine the possibility of its installation in specific premises.

Let's look at these questions in more detail.

The principle of operation of automatic powder fire extinguishing.

Extinguishing a fire when using such a system is achieved by the fact that a fine powder is supplied to the combustion zone by spraying it in the ignition zone. This achieves:

• cooling of the ignition area as a result of the transfer of part of the heat to the powder particles and the energy consumption for its melting;
• a decrease in the volume of incoming oxygen as a result of dilution of the burning medium by products of thermal decomposition of the powder;
• inhibition (slowing down) of the chemical reaction of combustion.

Depending on the composition of the powder mixture, various combinations of these factors can be achieved.

The supply of powder to the combustion zone can be carried out different ways. Most commonly used:

• gas supply high pressure;
• pressure as a result of the explosion of a pyrotechnic cartridge.

By the way, each of these methods has an additional extinguishing effect. The jet of gas and the shock wave of the explosion, in addition to supplying the powder, can also lead to flameout, which serves as a factor that increases the efficiency of the system.

Advantages of powder fire extinguishing.

First of all, they should include:

• simplicity of the device;
• low cost;
• wide operating temperature range and versatility of application.

However, there are a number of specific disadvantages that limit the scope of this method:

• low efficiency in extinguishing fires with combustion without air inflow in the thickness of the material;
• possible chemical interaction of the powder with metal structures;
• inability to use with a working ventilation system;
• potential hazard to human health.

The last point needs more clarification. Possessing low toxicity, fire extinguishing powder, however, due to its high concentration and small particle size, has a specific effect on the respiratory system of the body. Also important is the factor of a sharp decrease in visibility at the time of operation of fire extinguishing equipment and an increase in the possibility of panic.

Thus, the use of automatic powder systems is limited in human areas. Such installations can only be installed if people are evacuated before the start of fire extinguishing and if the system is manually turned on.

In general, the scope of powder fire extinguishing is quite wide, for example:

• extinguishing electrical installations without removing the voltage;
• fire extinguishing in archives, warehouses and other places of storage of valuable items and documents;
• extinguishing chemicals, oil products, etc.

It is not recommended to use powder fire extinguishing in industries where a large amount of equipment with small open contacts is concentrated (automatic telephone exchanges, relay control points).

MODULAR POWDER EXTINGUISHING SYSTEMS

Modular fire extinguishing systems are characterized by a number of positive aspects:

• small dimensions of the system as a whole;
• high reliability;
• ease of installation and maintenance;
• the possibility of spot installation directly near the object with a high fire hazard.

The fire extinguishing module is a housing filled with a powder mixture. In the upper part of the housing there is a gas generator, which is triggered after an electrical signal is applied. There are also modules that operate autonomously when the temperature is reached. environment certain level.

The lower part of the case is usually made of aluminum and has notches over the entire surface. When a signal is given to the gas generator, gas begins to flow into the body with the powder. After reaching a certain pressure, the membrane (lower part of the housing) is torn along the notch lines and the powder is thrown into the flame area. From the moment the signal is given to the ejection of the powder, a time elapses of more than 2 seconds.

By the way, there are versions of modular systems, in which the modules contain only a fire extinguishing mixture. In this case, the powder is ejected through a centralized gas supply through a specially equipped pipeline. This option is much more expensive and is not used as often.

The principle of operation of all modular systems is almost the same. The differences are in the volume of the body, which can range from 0.3 to 50 liters. In some designs, the lower part of the housing may not be destroyed. Instead of a bursting disc, a special nozzle is used, which serves to direct the powder jet.

Among the disadvantages of modular systems, it should be noted that this design, by definition, provides for a single use. If it was not possible to extinguish the fire the first time, then the use of other fire extinguishing means, including manual ones, is required.

INSTALLATION AND MAINTENANCE OF POWDER SYSTEMS

Design, installation and maintenance of automatic powder fire extinguishing systems is carried out by specialized organizations that have the appropriate licenses from the Ministry of Emergency Situations.

When drawing up a project, both the geometric parameters of the premises equipped with a fire extinguishing system and the possible classes of fires, which are determined by the presence of certain materials and factors in the premises, should be taken into account.

All premises equipped with automatic fire extinguishing must have a fire warning system, as well as information boards:

• "exit";
• "powder do not enter";
• "powder go away."

In addition, during installation, it should be taken into account that when the fire extinguishing module is started, the load on the supporting structure increases many times over. Its exact value is indicated in the technical documentation, but on average this value is about 3-5 masses of the equipped module. There should be no obstacles in the powder spraying area that restrict the access of the fire extinguishing mixture to the place of ignition.

All electric starting circuits must be able to continuously monitor their integrity and performance. In addition, the requirements for an automatic system fire alarm, controlling fire extinguishing is tougher than to working offline.

All this is determined by a set of regulatory and technical documents, which can be found here.

Maintenance of a powder fire extinguishing system consists in maintaining the operability of the system as a whole. The activities carried out for this purpose are determined by the list of routine maintenance work on fire extinguishing. Also, for a quick restoration of the system's operability, an exchange fund of modules is provided at the facility.

The number of spare devices depends on the size of the object and is determined by the already mentioned regulatory documents. It should be noted that this material provides only general idea on the device and installation procedure for automatic powder extinguishing.

Within the framework of one article, it is impossible to state all the subtleties and nuances of this process. But the main points to be noted in without fail, are indicated here.

© 2010-2018. All rights reserved.
The materials presented on the site are for informational purposes only and cannot be used as guidance documents.

The main purpose of automatic fire extinguishing installations is to eliminate the fire and start extinguishing the fire before the arrival of firefighters. If the AUPT system is correctly calculated and implemented, its actions will help to significantly minimize damage from destruction and prevent human casualties.

POWDER FIRE EXTINGUISHING SYSTEM

In order for the installation to be successful and correct in terms of safety, a future project is developed before all installation work.

"Mig-Montazh" carries out the design of AUPT with subsequent connection to the security and fire alarms inside the premises so that the fire extinguishing processes work as quickly as possible.

The principle of operation of the AUPT is that special sensors respond to the main factors of ignition (the appearance of smoke, a significant increase in temperature) and eliminate the sources of combustion with various fire extinguishing agents.

The systems function autonomously and do not require continuous human control, for this reason the installations react in as soon as possible and eliminate the spread of fire over vast areas, especially if there are a lot of flammable objects in the room.

What is taken into account in the design?

Where and how to implement automatic fire extinguishing installations - experts decide based on the wishes of the client and the parameters of the building.

Before making calculations and creating project drawings, the masters consider:

• The dimensions and number of storeys of the building or the area of ​​a specific room that requires the installation of AUPT;
• Number of rooms, offices, corridors and halls;
• Type of premises in accordance with fire hazard categories;
• Availability of employees, customers, visitors or residents and their average number;
• Characteristics technical equipment and previously installed systems.

In addition, the design of AUPT in Moscow takes into account all the requirements of the Ministry of Emergency Situations, safety standards and regulations and regulations.

Only in this case, the automatic installation will be the safest both during operation and in emergency situations, and its operation will become as efficient as possible.

Automatic fire extinguishing installations are suitable for buildings of any type and size, their importance will be especially noticeable in institutions where there are a lot of flammable valuables (libraries, archives, galleries) or a large daily flow of customers.

FIRE SYSTEMS

WATER - GAS - DUST

One of the most efficient systems firefighting are automatic systems fire extinguishers designed for rapid fire detection and effective flame extinguishing.

The design of such blocks includes fire detectors (mechanical type, electrical mode, etc.), the inclusion of complex sensors and special devices serving the fire extinguisher (pipelines and other modules).

The main functions of automatic fire extinguishing:

• timely detection, localization and fire control at the initial stage;
• preventing the spread of fire;
• protection of people, buildings and other material values.

An Automatic Fire Suppression System (AUPT) is a set of tools and equipment designed to extinguish fires and controlled signals.

As a rule, a fire extinguisher activates an alarm, which greatly increases the efficiency of the switching system, and timely evacuation of the fire zone is very important.

One of the advantages of an automatic system is that its integration does not depend on human factors and is only related to control signals that are usually generated by automatic fire alarms.

APCTs vary in type of substance and are used to extinguish:

• water or water with foam (water and foam);
• mixtures of inert gases that do not reach the ignition reaction (gas);
• a special mixture of dust that prevents combustion (dust);
• a mixture of inert gases and small particles (aerosol).

AUTOMATIC WATER AIR FIRE TYPES

This type of installation is one of the most common due to the availability and harmlessness of people, since the extinguishing agent is water or water with foam.

The mechanism of operation of such devices is as follows: when the fire goes out, the combustion temperature decreases.

When using a blowing agent, oxygen access to the flame is even more limited, which stops the reaction.

Water fire suppression systems can be created with water curtains that help contain gusts and also spray walls to increase fire resistance.

The disadvantages of automatic fire extinguishing systems are that water freezes at low temperatures, has good electrical conductivity (which makes it impossible to destroy electrical equipment). It may also damage certain categories of wealth.

Fire extinguishers can be of two types:

• sprinkler;
• floods.

Today, very popular systems use thin water (steam) as the fire extinguisher.

Such devices can be used in rooms where printed and handwritten texts are stored. A sprinkler is a syringe equipped with a special nozzle of melting material that melts when the temperature rises and opens access to water. Installation of devices is carried out in places where strong heat release during ignition is possible.

Immersion systems are installed in high explosive buildings.

Powder dust - system characteristics, principle of operation and classification

The syringe supply in this complex is always open, and the water supply signal is triggered by a fire alarm. With this type of fire suppression system, water curtains can be created that interrupt the ignition range.

Installing a fire to extinguish a fire requires laying pipelines, installing pumping stations and other special equipment, which leads to a significant cost of the system.

to come back to the beginning

PRODUCTION OF GAS FUEL

These systems show greater efficiency in the case of the initial stage of ignition.

In this case, the inert gas acts as a fire extinguisher, which does not cause a reaction with combustible materials and quickly fills the combustion zone. This reduces the oxygen concentration in the ignition source, which prevents the fire from spreading further.

The main advantage of a gas appliance is that during fire fighting with this system of material values ​​stored in a protected area, they are not damaged.

Inert gases (at certain concentrations) used in fire extinguishers do not threaten people and do not have a negative impact on the environment.

The disadvantage of such systems is that protected areas for effective measures fire extinguishers must be stable and not too bulky. When you turn on the complex, you must perform an evacuation.

Automatic fire extinguishing systems.

The aerosol fire extinguishing system is a good combination of the mechanism of operation of pulverized coal plants. The extinguishing agent is an aerosol containing a mixture of fine particles and gas.

When formed, this mixture forms a burner that has the properties of blocking a chain reaction in the ignition range.

Aerosol plants should not be used to extinguish substances that can burn and ignite spontaneously without access to oxygen. It should also be remembered that the process of obtaining an aerosol mixture takes place at a high temperature, which can cause secondary fires.

It is forbidden to install such systems in areas where more than 50 people can be at the same time. The fire extinguishing system should not be installed in rooms where they may not have enough time before turning on the aerosol unit.

And also in buildings of a special type, the fire resistance index of which is below the third level.

to come back to the beginning

AUTOMATIC DISHWASHER

In these systems, a special powder is used as a fire extinguishing agent, which, when exposed to high temperatures decomposes into non-combustible substances that prevent the burning of the flame. The advantage of such complexes is quite simple to install. When using them, there is no need to turn off the voltage.

However, these systems have many drawbacks to consider when installing:

• for the human body, the threat is an inhalation powder;
• air movement in the fire zone can change the geometry of dust distribution and reduce the effectiveness of fire extinguishing;
• pieces of furniture and other barriers can create areas that prevent the delivery of a fire extinguisher;
• the system cannot guarantee complete flame extinction in the presence of materials that can be pressurized and ignite spontaneously without access to oxygen.

The powder for extinguishing the device can be modular (the extinguishing agent is stored in special modules contained in the ceiling) and centralized (the substance is stored in special tanks and supply pipelines).

Instead of closing.

APCT has improved the efficiency of fire detection and elimination. The main advantage of the complexes is full automation. The design and further installations must be carried out by trained personnel, as this determines the efficiency and safety of the device.

Violation of the requirements for planning, placement, non-compliance with regulatory documents may have Negative consequences for the health and life of people.

Some fire extinguishing systems operate in hermetically sealed rooms and require the evacuation of personnel before switching on. Therefore, the time between the start of the APCT and the evacuation of people should be sufficient, but not exceed certain parameters, since the longer the period, the stronger the fire.

Reconciliation of these two criteria can be achieved by right choice type of fire extinguishing, separation of the protected object in localized areas, which will allow the most efficient use of the complex. The facility must be equipped with early warning systems.

A properly prepared and consistent evacuation plan must be established.

to come back to the beginning

© 2014 — 2018 All rights reserved.

The material on the website actually finds and cannot be used as guidelines and white papers

The fire extinguishing system largely depends on only one factor - the type of medium used to localize and eliminate the fire. Other factors - the degree of autonomy, the nuances of the control system, installation schemes and configurations - are obviously secondary.

Of course, they affect the installation of fire extinguishing systems, but they do not affect the technology for eliminating the source of fire.

powder dust

Therefore, in this article we will take into account the construction of fire extinguishing systems, which are classified according to the central power supply scheme, which prevents the combustion process.

Powder fire extinguishing system

In dust systems, a fine dispersion based on carbon monoxide is used as a preventive agent. This powder is ejected from the body in the form of a bowl attached to ceiling structure and diffuse along the supporting surface.

After that, the powder dissolves in the maximum possible range under the influence of weight. The flexible force that atomizes the dust creates a compressed gas.

Powder fire extinguishing system

As a result, the device consists of a housing with an external nozzle directed parallel to upper limit, inside a cassette with carbon dioxide dust from several nozzles and a compressed air reservoir located in the central part of the body.

Such an installation operates in a pulsed mode, assuming a short-term periodic injection of a fine powder. .

In addition, dust installations at the installation site have no contraindications - such devices are installed in libraries, data processing centers, and electronic stores. The hardening procedure is possible at 50 degrees of frost and 50 degrees of heat (Celsius).

Gas fire extinguishing system

Such a fire extinguishing system is as simple as a bicycle.

In fact, this is an ordinary cylinder with carbon dioxide, the valve is controlled by a servo with a fire sensor. In crisis situations, the cylinder opens and the heavy carbon dioxide falls to the ground or "flies" into the room, so that oxygen from the combustion space is moved. Well, without oxygen - the universal oxidizing agent - there are no burns. And gas systems work practically without errors - they have no moving parts - the main cause of accidents is a complex and simple mechanism.

Scheme of an automatic fire extinguishing system

The supply force that ensures the atomization of carbon dioxide causes the medium itself, the pump in the cylinder, to be pressurized.

At the same time, the fire extinguisher system can be used everywhere in gases - it cannot harm either the "burnt" or the surrounding objects. Therefore, automatic fire extinguishing systems are also used in museums.

However, in living rooms, schools, kindergartens and offices, such systems should be used very carefully - carbon dioxide can be "suffocated" not only by fire, but also by residents or staff who simply cannot survive without oxygen supporting oxygen.

Such is our human nature.

Water fire extinguishing systems

Installation of fire extinguishing systems on water is justified if the owner of the protected property is important lives people, not the safety of equipment or inventory.

After all, water can't submerge fire, but it will also hurt everyone, of course, except for humans.

Water fire extinguishing systems

From the water, all electronic equipment, mechanisms made of structural steel and cast iron, brown furniture and food.

But the man remains intact. In addition, artificial "rain" provides high ignition efficiency of the ignition source located on early stages. Also, the humid environment - and when the water system is activated, everything gets wet in seconds - is very reassuring.

This system is technically organized also lighter analog gas - an injector mounted on the ceiling, the supply pipe is connected to the manifold by a pump station, or water towers.

When triggered, the sensor opens the shut-off devices installed in water valves, valves, etc. and directs the flow of water through pipes to the point of incineration.

Defoamer

This system was created during the development of the water plant. In this case, instead of completely destroying the water, it touches this medium from a nozzle or simply polystyrene foam- a supersaturated surface solution consisting of well-bound "soap" bubbles.

Defoamer

And this "bubble" mass contains a minimum amount of water and causes minimal destruction.

Therefore, foam can be used to extinguish even electrical appliances and museum exhibits. In this case, unlike carbon dioxide and carbon monoxide, the foam not only does not harm facilities, but also traps untrained tenants or employees.

Technically, such a fire extinguishing system is regulated by the model of the water supply system. Only the bell has a water hose connected not to a spray nozzle, but to a foam generator.

Installation of fire protection systems

It is hard to imagine a modern building without a complex technical means ensuring his life. One of the key places in it is the fire safety system.

Why fire fighting equipment is needed

Fire safety is a mandatory attribute based on the requirements of the laws of the Russian Federation.

No matter what high-quality and innovative materials are used in the construction and decoration of premises, and technological processes are thoroughly verified, there is always a risk of fire.

Firemen's website | Fire safety

All modern construction standards provide for the installation of fire safety systems at any facility. Their tasks include:

• Notifying people at the facility about a fire;
• Coordinating the actions of personnel to localize the fire and ensure evacuation;
• Transmission of a fire signal to fire departments;
• Extinguishing the fire with the help of automation.

Each object has its own tasks, but they have one goal - to provide protection in the event of a fire, minimize property damage and stop harm to health or death of people.

What to put

Depending on the specifics of a particular object, the choice of equipment for the installation of fire protection is carried out.

The simplest system for a small room can be presented in the form of autonomous smoke detectors that allow people to be notified about the start of a fire upon detection of one of its signs - smoke.

For larger facilities, automated fire safety systems are required to monitor the situation around the clock and automatically respond to an emergency.

They include not only fire alarm systems (APS) and alerts, but also fire extinguishing, smoke removal systems and are integrated with other engineering networks.

For example, integrated system the security of the facility in the event of a fire in the room, automatically transmits a signal to the nearest fire department, the access control system unblocks the evacuation routes, the automatic ventilation will turn off the air exchange and switch to the smoke removal mode, and video surveillance will switch to the premises at risk to control the evacuation.

In the case of equipping the facility with automatic fire extinguishing, then with the help of security sensors, people in the room will be monitored, and, in their absence, the fire extinguishing composition will be discharged.

Stages of creation

The installation of fire protection systems involves several stages:

• Determining the required level of security;
• Statement of technical specifications;
• Project development, if necessary, integration with project documentation on other building systems;
• Selection of fire equipment;
• Installation of all components;
• Commissioning with mandatory checks, both of individual sections and of the entire system as a whole;
• Control launch, acceptance by authorized state bodies;
• Warranty service.

On already installed complexes, regular maintenance work is mandatory, only in this case it can be guaranteed that in the event of an emergency, the automation will work as it should.

It is advisable to trust such preventive work to the same specialists who carried out the installation. they know all the features and can predict in advance possible reasons faults.

Who can put

The installation of fire safety systems is the lot of specialists, since this is a licensed type of activity and such services cannot be provided without special permission. But the presence of a license does not always indicate the professionalism of the installers.

To date, several hundred companies in Moscow offer their services for the installation of fire protection equipment and it is necessary to choose the best offer, not only in terms of price, but also in terms of quality. The following criteria will help you choose:

• Availability of a license for all types of services in the field of fire safety equipment;
• Trained staff with experience;
• The ability to select the necessary equipment and the skills of its maintenance;
• Willingness to develop a project and coordinate it with supervisory authorities;
• Provision of technical service.

It is not worth saving on the installation of fire-fighting complexes; people's lives depend on their work.

The sad events of the past few years, where fires led to the death of several dozen people, serve as another proof of this. Modern equipment fire safety can prevent such tragedies, but subject to several conditions. First, high-quality and certified equipment. Secondly, correct installation: from design to installation. Thirdly, constant professional service. With these settings, you can big share confidence to consider the object as protected as possible from troubles with fire.

Price from 90 rubles/m2 - depending on the complexity of the layout of the object.

Many, when choosing materials for the construction of a private house, do not pay attention to their fire resistance indicators and use flammable materials for arranging premises, which, when burned, also emit toxic substances.

If you install a fire extinguishing system in your home, you can minimize the damage from a fire. At the moment, there is no regulatory documentation that would talk about equipping private houses with automatic fire extinguishing devices, so the installation of such systems in private buildings is considered optional. However, there are no regulations prohibiting this.

Choice of fire extinguishing system

When choosing a fire extinguishing system, you need to rely on two important criteria: the first is the efficiency of the entire system, and the second is minimizing damage to property from fire extinguishing agents.

Fire extinguishing systems can be water (which puts out the fire with water), powder and aerosol.

From the point of view of damage to property from the means of the fire extinguishing system itself, the use of a water system is not very attractive, because what is not spoiled by fire will be spoiled by water. At the same time, the water used to extinguish the fire gets not only into the place where there is a fire, but also into other rooms, for example, on the floor below.

Powder fire extinguishing modules - principle of operation and triggering conditions

Also, the disadvantage of this system is the fact that it cannot be used in cold rooms, i.e. in the country, which is operated only in the summer.

Powder fire extinguishing systems spray powder in case of fire. They act as follows: the sprayed powder on burning surfaces is fused into a single mass over the fire, thereby blocking its access to oxygen.

Aerosol fire extinguishing devices spray special substances, which, when released into a fire, turn into a mixture of particles (finely dispersed) and inert gases. These particles inhibit oxidation reactions and block oxygen from the fire, while inert gases reduce the amount of oxygen in the room.

The above devices, in addition to their features, also have certain requirements regarding their installation, for example, it is worth considering the height of the modules, the need to connect to communications, etc.

e. Therefore, it is necessary to make a choice and install a fire extinguishing system only in consultation with a specialist.

Of course, an important factor when choosing a fire extinguishing system is the cost.

However, this criterion should be followed last. After all, cheap systems do their job quite well, as well as expensive ones. But the problem may lie elsewhere - cheap systems often fire when it is not necessary and the damage from their operation can be caused much more than if a fire actually occurred.

In addition, due attention should be paid to the type of start of the fire extinguishing system. On this basis, the devices are divided into 2 groups - modular autonomous and system.

Autonomous devices are triggered at the moment of reaching the critical temperature regime in room. They can be installed even in those buildings where there is no power supply. The disadvantage of these systems is that the modules react to fire alternately.

First, the module that is as close as possible to the fire site is triggered. Then, when the flame reaches another module, it also fires. The fire extinguishing system modules always operate at the same time. They are autonomous and dependent. Dependents are triggered by signals from several sensors.

1.1. Features of the use of powder in automatic fire extinguishing installations.

Powder fire extinguishing installations are designed to extinguish fires of alcohols, petroleum products, alkali metals, organometallic compounds and some other combustible materials, as well as various industrial installations energized up to 1000 V.
The installations can be used to extinguish fires in industries where the use of water, air-mechanical foam, carbon dioxide, freons and other fire extinguishing agents is ineffective or unacceptable due to their interaction with combustible products circulating in production.
Fire extinguishing powders are not recommended for use in extinguishing fires in rooms where there is equipment with a large number of open small contact devices, as well as in rooms in factories where combustible materials that can burn without oxygen are handled.

Fire extinguishing powders are finely ground mineral salts with various additives that prevent caking and clumping. They have a number of advantages over other fire extinguishing agents:
- high fire extinguishing ability, as they are a strong flame retardant;
— versatility of application;
- a variety of fire extinguishing methods - volumetric, local or local-volumetric.

There are powders of general and special purpose. Powders general purpose designed to extinguish fires of combustible materials of organic origin (flammable and combustible liquids, solvents, liquefied hydrocarbon gases, etc.), solid materials, etc. These materials are extinguished by creating a powder cloud above the combustion source. Special purpose powders are used to extinguish certain combustible materials (such as metals) whose combustion is stopped by isolating the burning surface from the surrounding air.

The fire-extinguishing ability of general-purpose powders increases with an increase in their dispersion, while special-purpose powders almost do not depend on their degree of dispersion.
The effect of extinguishing fires with powder compositions is achieved due to:
- dilution of a combustible medium with gaseous decomposition products of a powder or directly a powder cloud;
- cooling of the combustion zone as a result of heat consumption for heating the powder particles, their partial evaporation and decomposition in the flame;
- inhibition of chemical reactions that cause the development of the combustion process, gaseous products of evaporation and decomposition of powders or heterogeneous chain termination on the surface of powders or solid products of their decomposition.

It is generally accepted that the ability of powder formulations to inhibit flames plays a major role in extinguishing.
Successful extinguishing of a fire with a powder depends not only on the properties of the powder itself, but also on the conditions of its use. Under the conditions of use is understood the suitability of the powder for extinguishing a given combustible material and the mode of supply of the powder to the fire. The suitability of a powder is characterized by the compatibility of the powder with combustible materials. For example, sodium bicarbonate powder is suitable for extinguishing class B, C, E fires, but not suitable for extinguishing smoldering materials; MGS powder effectively extinguishes burning sodium, but it cannot extinguish potassium and a number of other metals, etc.

The supply mode is characterized by the following parameters: the specific amount of fire extinguishing agent, the intensity of the supply of fire extinguishing agent and the extinguishing time. In addition, when choosing the powder supply mode and extinguishing method, it is necessary to take into account the nature of combustion and the properties of the combustible material. For example, when extinguishing class fires
B and C, which are characterized by inhibition of combustion, the most effective method of supply is the creation of a fine atomized cloud. In this case, a uniform distribution of the powder in the volume of the protected room is required. The powder must be supplied in atomized state, which is achieved special nozzles and displacing the powder from the vessel under high pressure (not higher than 1.6 MPa). When extinguishing class D fires, spilled flammable and combustible liquids, the powder must be supplied with a jet with low kinetic energy in order to evenly cover the burning surface without spraying and blowing the powder. In this case, high pressure for the supply of fire extinguishing powder is not required and vessels designed for low pressure (up to 0.8 MPa) can be used.

The main requirements for fire extinguishing powders include not only the efficiency of extinguishing the flame, but also the ability to maintain their properties for a long time. Like many highly dispersed materials, fire extinguishing powders during long-term storage undergo various changes that worsen their quality: caking and clumping. Powder caking occurs as a result of exposure to moisture and ambient temperature. In the process of absorption of moisture from the air by the powder and subsequent dissolution of powder particles in condensed water, saturated solutions of the solid phase are formed. With a further increase in the amount of moisture, the solution becomes supersaturated, and crystals of the initial solid phase precipitate out of it in the zone of particle contact. Then, as a result of the formation of phase contacts, the crystals coalesce.

The crystalline powders of low hardness, which include fire-extinguishing ones, are also affected by the plastic deformation of the particles, as a result of which the formation of phase contacts from point contacts proceeds under the action of elevated temperatures and compressive forces (for example, its own mass). The caking effect is affected by the size of the particles, their uniformity and the nature of the surface. The tendency to caking increases with decreasing particle size. When compacting the powder, small particles, by clamping the pores between large particles, increase the number of point contacts, which leads to a higher caking ability. Thus, the fire-extinguishing efficiency of powders depends not only on the inhibitory ability and dispersion, but also on the conditions of storage and transportation. The operational properties of fire extinguishing powders also include moisture (absorption of air moisture), fluidity (transportation through pipelines and hoses), compressibility (powder compaction under load), vibration resistance (retention of properties after exposure to controlled shrinkage), bulk density, compatibility with foams ( the degree of destructibility of the foam in contact with the powder), electrical conductivity, corrosivity, toxicity. There are several ways to combat caking, which are reduced either to reduce the moisture content in the powder, or to reduce the number and area of ​​particle contacts. These include the removal of moisture by drying, the packaging of powders in waterproof containers, the use of water-repellent (hydrophobic) and water-absorbing agents, as well as additives that improve flow. It is possible to improve the performance and, as a result, the fire-extinguishing properties of powders not only by introducing special additives, but also by improving the technology of their manufacture.

1.2. Automatic powder fire extinguishing modules

Powder fire extinguishing module (MPP) is a device that combines the functions of storing and supplying fire extinguishing powder when an actuating impulse is applied to the trigger element. Modules according to the method of organizing the supply of a fire extinguishing agent can be with a collapsible (P) or non-collapsible (N) body.
According to the time of action (the duration of the supply of OTV), MPP can be of fast action (pulse - And) or short-term action (KD-1 and KD-2).
According to the method of storage of the displacing gas, MPPs are divided into injection (Z), with a gas generating (pyrotechnic) element (GE, PE), with a cylinder of compressed or liquefied gas (CLG).
MPP with a collapsing hull, shown in fig. 1, a, has a weakened lower part of the body. Under the influence of a command pulse, the gas generating device is turned on, the pressure inside the case increases and the weakened part collapses and releases the powder into the protected room. This design allows to significantly reduce the weight, however, after operation, the module cannot be restored.

Rice. one. Powder fire extinguishing modules:
a - with a collapsing body:
1 - collapsing hemisphere;
2 – module fastening;
b - with a non-destructive body:
1 - container for powder;
2 - spray nozzle;
3 - module mount

MPP with a non-destructive body, shown in fig. 1b has a special membrane and nozzles. When a command pulse is given, the gas generating device creates pressure in the housing and the membrane is destroyed. The powder comes out of the housing and is sprayed through the nozzle on a given area. After use, the module is recharged with powder and a new membrane is inserted into it.
On fig. 2 shows a module with a large amount of powder (up to 100 kg).

Rice. 2. MPP-100 powder fire extinguishing module:
1 - container with carbon dioxide;
2 - squib;
3 - starting head;
4 - safety valve;
5 - powder filling neck;
6 - pipe;
7 - a cylinder with a capacity of 100 dm 3 with fire extinguishing powder;
8 - conditioner;
9 - air valve;
URP-7 - manual start device, included in the MPP-100 kit

A module of the MPP-50 or MPP-100 type (see Fig. 2) is a steel welded cylinder 7 welded to the frame for powder poured through the neck 5 in the upper part of the cylinder. Pipe 6 is used to connect the powder pipeline with spray nozzles. A safety valve 4 is mounted in the neck cover. A cylinder 1 with carbon dioxide or nitrogen is attached to the cylinder 7 with powder, under a pressure of 0.8 MPa (8 kgf / cm 2), which is necessary to deliver the powder to the protected room. The gas from the cylinder 1 enters under pressure into the cylinder 7 with powder using the starting head 3 with a squib 2, which are switched on from the electric start system or from the manual start device of the URP. In the event of a fire due to an increase in temperature or when an open flame appears, the fire alarm system opens the shut-off and starting device 3 of the cylinder 1. Gas from the cylinder enters the internal cavity of the housing 7 with powder. In the housing, the powder passes into a fluidized state with the help of a fluffer 8, due to which it acquires the ability to flow through the distribution pipeline. When the pressure in the fire extinguisher body rises to 0.8 MPa (8 kgf / cm 2), the pneumatic valve 9 is activated, after which the powder from the body, through the siphon tube present in it, enters the distribution pipeline, then to the spray nozzles, and then to the protected area (in volume).
The module is equipped with a manual start device URP, which turns on the module through a starting head with a squib.

1.3. Powder fire extinguishing installations

Powder fire extinguishing installations consist of one or more modules and are divided into the following types:
- installations with a centralized source of working gas;
— installations with autonomous sources of working gas on each module.

Installations of the second type, in turn, are divided into:
- installations with simultaneous start-up of all modules included in its composition;
- installations with selective (single) start-up of modules depending on the place of fire.

Powder fire extinguishing installations are predominantly local fire extinguishing installations.
The installations must have a 100% reserve supply of fire extinguishing powder and working gas, located directly in the modules and ready for immediate use in cases where re-ignition of combustible material is possible (for example, with a continuous supply of flammable liquid with an autoignition temperature of 773 K and lower, in the presence of combustible substances and materials heated to a temperature that increases their self-ignition temperature, etc.). In all other cases, a 100% reserve supply of powder and working gas may be stored separately from the modules.

As modules for installations, automatic powder modules with a single source of working gas or modules with an electric start or with a cable start system.
Installation with a centralized source of working gas consists of the following assembly units:

1) modules containing a container with a fire extinguishing powder with a capacity of 100 liters, equipped with shut-off control and safety valves, as well as a distribution network with spray nozzles.
As modules for installations of this type, automatic powder fire extinguishers of a modular type are used. The number of modules depends on the required amount of fire extinguishing powder;

2) a centralized source of working gas containing containers (cylinders) for storing working gas, equipped with automatic shut-off and starting valves and a control device. Batteries and gas fire extinguishing installations can be used as a centralized source of working gas. If necessary, the capacity (power) of the working gas source can be increased by attaching stacked sections to the battery;

3) a collector containing a main pipeline with branches and designed to supply working gas from a centralized source to the modules;

4) switchgears designed to supply working gas to the required group of modules;

5) automatic fire alarm installations with heat, smoke and flame detectors, designed to detect a fire and issue signals to turn on the shut-off valves of a centralized source of working gas and switchgear, as well as sound and light alarms;

6) electric control unit of the installation.

Installation with an independent source of working gas includes the following assembly units:

1) modules containing a container with fire extinguishing powder of various capacities. A container equipped with an independent source of working gas with a shut-off and starting device, as well as control and safety equipment. Distribution network with spray nozzles.
As modules for installations of this type fire extinguishers of modular type with electric start are used. The number of modules in the installation is determined by the required mass of fire extinguishing powder;

2) an automatic fire alarm installation with heat, smoke and flame detectors, designed to detect a fire and issue a signal to turn off the ventilation systems, to turn on the shut-off and starting devices of autonomous working gas sources, as well as sound and light alarms;

3) power supply unit of the installation;

4) cable network to supply a start signal to each module.

The installation with an independent source of working gas includes a set of modules commercially produced. Installations have a fixed charge of fire extinguishing powder. The value of the protected area (volume) is determined technical specifications modules included in the installation.
It is recommended to use carbon dioxide, nitrogen or air as the working gas for installations. Air and nitrogen must be dehydrated.
The moisture content is allowed not more than 0.01% by weight.
All types of installations are allowed to operate in standby mode only if they are provided with a working gas charge in an amount not less than that allowed by the passport for the module for individual sources of working gas and for gas batteries for a central source.

The coefficient of filling module cases with fire-extinguishing powder (ratio of powder volume to case capacity) should not exceed 0.95.

1.4. Electric control of powder fire extinguishing installations

Electrical control equipment for an installation with a centralized source of working gas must provide:
- constant readiness of the installation for action in the event of a fire in the protected room;
- detection of a fire with an indication of the place where it occurred;
- issuing a fire signal to the control room of the facility and to the fire department, as well as a warning signal within the protected premises to ensure the evacuation of people;
- delay in the automatic start-up of the installation for the time necessary for the evacuation of people from the protected premises, in accordance with the requirements of the current building codes and regulations;
- automatic start-up of the installation for issuing the main supply of fire extinguishing powder from the fire alarm receiving station;
- repeated remote start-up of the installation for issuing a reserve supply of fire extinguishing powder;
- manual (in place) start-up of the installation with a completely disconnected electricity;
- the ability to disable automation and transfer the installation only to manual start;
- issuance of a signal about the inclusion of the required direction of the working gas supply, about the movement of gas, as well as about the start of the modules.

The supply of electricity to all receivers of the installation must be carried out according to the first category in accordance with the requirements of the PUE.

2. Calculation of powder fire extinguishing installations

2.1. Design features of powder fire extinguishing installations

Features of the design of powder fire extinguishing installations are as follows.
The type of installation is selected depending on the characteristics of the fire hazard of the protected technological process. The brand of powder and the method of extinguishing (surface, volumetric) are accepted, guided by reference data for powders.
The type of drive (cable or electric) is accepted depending on the fire hazard category of the protected premises. The electric start of the UPPT in fire and explosion hazardous premises with industries of categories A and B is permissible only in the case of the use of explosion-proof fire detectors. Manual remote start devices (buttons, levers) should be located at the exit from the protected room and protected from accidental activation.

The modules may be placed directly in the protected area. Installations can be placed on technological platforms, whatnots, galleries or on special brackets. At the same time, the distance from fire extinguishers to technological equipment must be at least 5 m. If there is a shortage of production space, as an exception, the specified distance can be reduced to 3 m.

Pipelines of the distribution network are painted in gray, pneumatic communications - in blue, control and signaling units - in red.
If the total area of ​​open (during fire extinguishing) openings is more than 15%, then only surface (local) extinguishing is accepted.
The thermomechanical system for starting fire extinguishers is placed both along the distribution network on rollers and directly under the protected equipment. The distance from the fusible lock to the nearest roller towards the fire extinguisher must be at least 0.6 m.

The manual start unit for fire extinguishers with a thermomechanical system is located at a height of 1.2–1.5 m from the floor in easily accessible places on escape routes, and in protected rooms - near the exit from them.
An inscription is posted near the manual start unit: “In case of fire, pull out the pin and lower the handle to the lower position”, etc.

2.2. Calculation of automatic modular type powder fire extinguishing installations

The calculation begins with the determination of the cross section area of ​​the collector. With its length from a centralized source of working gas to the first module (up to 100 m), it is calculated depending on the number of modules connected to it:

(5.1)

where f - cross-sectional area of ​​​​the collector, cm 2;
0,632 - empirical coefficient, cm 2, taking into account the gas flow rate per module, pipeline resistance, etc.;
n – number of modules, pcs.

If the length of the collector from the centralized source of working gas to the first module is more than 100 m, the flow area of ​​the collector is calculated using general formulas.
It takes the following data:
- gas consumption per module 75 l s -1 ;
— initial gas pressure in the centralized source 12.5 MPa, residual gas pressure in the source 1.5 MPa.

In volumetric powder fire extinguishing, the number of modules is determined based on the required amount of powder and a single charge of the module:
(5.2)

where M p, M opa - respectively, the required mass of the fire extinguishing powder and the mass of the module charge, kg;
V to – capacity of the module body, m 3 ;
? – powder bulk density, kg/m3;
K zap - safety factor, taken equal to 0.35–0.95.

The mass of fire extinguishing powder Mn is determined by the formula

where K = 2 - with the possibility of re-ignition, in other cases K = 1;
V def - the volume of the protected premises, m 3;
qnv - volumetric fire extinguishing ability of the powder, kg / m 3;
f pr - the area of ​​openings opened during a fire, m 2;
q nadd - the norm of the additional mass of the powder, is taken equal to 2.5 kg / m 2 at fpr \u003d 1–5% and 5 kg / m 2 at fpr = 5–15% of the area of ​​​​enclosing structures. With a larger ratio of areas, it is recommended to use local fire extinguishing. In this case, an additional amount of powder, as a rule, should be used to organize a curtain of powder jets at open openings.

When determining the volume of the protected premises, it is allowed to subtract from its geometric volume the volume occupied in it by non-combustible building structures that do not have an internal volume that communicates with the volume of the protected premises.

In case of local fire extinguishing by volume (outside technical unit or equipment) the estimated volume V l is determined by the formula

where a, c, h - respectively, the length, width and height of the protected unit or equipment, m.

Nozzles for the release of powder during volumetric fire extinguishing should be placed in such a way that the powder is evenly distributed throughout the entire volume of the protected room; in case of local fire extinguishing by volume, powder jets should be directed to the surface of the equipment located in the protected volume.

The total number of moduli N mods for powder quenching by area (surface) is defined as the largest of two values:

where N mod1 - the number of modules, determined by the required amount of powder;
N mod2 - the number of modules, determined by the ratio of the entire protected area and the area protected by one module.

Number of modules N mod1 is determined by formula (5.2). Powder weight M p is determined by the formula

(5.6)

where K – has the same meaning as in formula (5.3);
F def - protected area of ​​the premises or equipment, m 2;
qn.f - surface fire extinguishing ability of the powder, kg / m 2.

The number of modules N mod2 is determined by the formula

(5.7)

where K and b> F def are the same quantities as in formula (5.6);
F1 - the area protected by one nozzle, m 2;
n - the number of nozzles in the module.

In order for the entire protected area or surface of process equipment to be sprayed with fire extinguishing powder, the distance from the nozzles to the enclosing structures should not exceed 1.5 m. The distance from the protected surface (area) to the nozzle should be at least 2 m and not more than 4.5 m .

The greatest extinguishing effect is achieved at a distance of 3.0–3.5 m. If the protected room has technical platforms and ventilation ducts with a width or diameter of more than 0.75 m, additional modules should be installed under it, taken into account when calculating according to formula (5.7) .

Note that if the number of modules determined by formula (5.5) differs slightly from an integer, then it can be reduced to an integer by varying the fill factor of the module Kzap or by simply rounding the number of modules up.
The number of modules determined by formula (5.7) is always rounded up.

2.3. Calculation of impulse powder fire extinguishing installations

The calculation of powder fire extinguishing installations of pulsed local type is carried out in accordance with the methodology. Number of pulsed powder modules (MIP) N l , pcs., is determined by the formula

(5.8)

where S y - the area of ​​the protected area (zone), for equipment, the area of ​​​​the equipment dimension, increases by 10%, m 2;
S n - normative area, m 2;
K1 - coefficient of uneven spraying of the powder, used in the group installation of the MIP, is taken equal to 1.2;
K2 - safety factor that takes into account the shading of a possible source of fire and depends on the ratio of the area shaded by the equipment S z to the protected area S y, is determined by the formula

(5.9)

where S - shading area, defined as the area of ​​the part of the protected area, where the formation of a fire seat is possible, to which the movement of powder from the MIP in a straight line is blocked by structural elements that are impermeable to the powder.

K3 - coefficient taking into account the change in the fire extinguishing efficiency of the powder used in relation to the combustible substance in the protected area compared to A-76 gasoline (Table 5.1);
K4 - coefficient taking into account the degree of leakage of the room. K 4 \u003d 1 + B F neg, where F neg \u003d F / F pom - the ratio of the total area of ​​​​leakage (openings, slots) F to the total surface of the room F pom, the coefficient B is determined from fig. 5.3.

Regulatory area S n is determined by the formula

(5.10)

where V n - the volume protected by one MIP of the selected type, m 3;
K5 – coefficient characterizing the characteristics of the spraying of the MIP powder of the selected type (determined by the technical documentation for the MIP).
If the equipment height in the protected area exceeds 1.4 H (where H is the discharge height) for the selected type of MIP, the latter are installed in tiers with a step at a height of 0.8 ... 1.4 H, provided that their placement should ensure uniform filling with powder protected volume. MIP can be installed on suspended structures. At the same time, constructive measures must be taken to prevent the consequences of the impact on the suspension elements of the dynamic force that occurs when the MIP is triggered, equal to five times the weight of the installed modules.
V n and H are accepted for the MIP of the selected type in accordance with the specifications of the developer-manufacturer.

Calculation of powder fire extinguishing installations of impulse volumetric type.

Number of MIPs N , pcs., necessary to protect the premises, is determined by the formula

(5.11)

where V p is the volume of the protected premises, m 3;
V n - the volume protected by one MIP of the selected type, m 3;
N p - the number of MIP required to neutralize the leakage of fire extinguishing powder through permanently open openings, pcs.
The values ​​of the coefficients K 1 and? K 3 are determined in a similar way to the calculation of the local-type RFID.

Table 5.1

Coefficient K 3 of the comparative effectiveness of fire extinguishing powders when extinguishing various substances

When protecting open technological installations as Sn is taken the area of ​​the maximum rank of the source of class B, the extinguishing of which is provided by the data of the MPP (determined according to the technical documentation for the MPP, m 2).

If fractional numbers are obtained when calculating the number of modules, the next larger integer in order is taken as the final number of modules.
For offline installations fire extinguishing, simultaneous group launch of the entire number of modules N, obtained by calculation, should be ensured.

3. Features of placement, installation and operation of powder fire extinguishing installations

3.1. Requirements for the placement of equipment for powder fire extinguishing installations

The centralized source of working gas, the fire alarm installation and the electrical control unit of the installation should, as a rule, be located in special rooms that meet the following requirements:
— fire resistance limit of walls and ceilings not less than 0.75 h;
- height not less than 2.5 m;
— a floor with a hard surface that can withstand the load from the installed equipment;
— air temperature within 288–309 K;
— illumination not less than 150 lx;
- the environment is non-explosive.

Before front door a lamp and a scoreboard should be installed outside. In cases justified by the project, the specified assembly units of installations, except for the fire alarm receiving station, can be placed in industrial fire-safe rooms. In this case, they must be fenced with a glazed partition or metal mesh and equipped with warning signs.

Modules should be installed, as a rule, in a room adjacent to the protected one. The room in which the modules are located must be separated from the protected room by a partition with a fire resistance of at least 0.75 hours. Openings in the partition must be protected by fire-resistant doors with a fire resistance of at least 0.75 hours. allowed to attach to building structures building.

The manifold for supplying working gas and cable wiring are recommended to be laid along overpasses together with other technological wiring. The collector and cable network must be protected from mechanical damage.

Nozzles for the release of powder during volumetric fire extinguishing should be placed in such a way that the powder is evenly distributed throughout the entire volume of the protected room. Spray nozzles must be placed in such a way that the powder jets are directed to the surface of the equipment located in the protected volume.

In case of local fire extinguishing, nozzles should be placed so that in case of fire the entire surface of the protected technological equipment or protected area is evenly dusted with fire extinguishing powder.

Devices for remote start-up of installations (buttons, levers) should be placed at the entrance to the protected room with protection from accidental use.

3.2. Requirements for protected premises

Protected premises should have, if possible, the minimum area of ​​openings open during fire extinguishing. Windows and doors must have automatic closers.
Ventilation openings in case of fire should be automatically closed, and the ventilation system should be turned off when the fire extinguishing installation is triggered. In relation to installations of type 2b, this requirement is not feasible. In this case, it is necessary to compensate for possible powder leaks with its additional amount: with a total area of ​​openings of 1–5% of the total area of ​​walls, ceiling and floor of the room - by 2.5 kg per 1 m 2 of an open opening; with a total area of ​​​​openings of 5–15% - by 5 kg per 1 m 2.

Ways of evacuation of people from the premises must provide an exit service personnel for no more than 30 s. If this requirement is not feasible, then a device must be introduced into the automatic control circuit of the installation to ensure the delay in the release of fire extinguishing powder until the end of the evacuation of people from the protected premises.

3.3. Requirements for installation, testing and commissioning

Installation of the units must be carried out in accordance with the working drawings of the project and the installation instructions attached to the supplied assembly units. Deviation from the project or installation instructions is allowed only upon agreement with the design organization and with the manufacturing plants of assembly units.

All assembly units must be subjected to incoming inspection in accordance with the requirements specifications and passport assembly unit.
Installation of the units must be carried out by trained personnel using special tools and equipment to ensure the proper quality of work.
Need to keep a journal installation work, which indicates the brand of the installed equipment, defects in this equipment identified during installation, last name, first name, patronymic and position of persons responsible for installation from among the leading technical personnel.
The journal notes all deviations from the project or installation instructions, as well as documents authorizing these deviations.

The installation of all pipelines must ensure: the strength and tightness of the pipe connections and the points of attachment of devices and fittings to them, the reliability of fastening the pipes to the supporting structures and the structures themselves on the bases, the possibility of their visual inspection, as well as their periodic purging.

When installing the collector pipelines, it is necessary to use detachable connections. Allowed welded joints, providing conditions for the movement of compressed gas.
The quality of installation work should be checked at the end of each operation by external inspection and pneumatic tests in accordance with the instructions of the passport of the assembly unit.
The working gas supply manifold must be subjected to pneumatic testing pressure 10.0 MPa for 120 s. Leakage of gas at the junction of the pipeline is not allowed. Leak control is carried out by washing the joints.
After completion of installation work and testing for strength and density, pipelines must be painted first with protective paint, and then with identification paint. Identification paint must comply with the requirements of GOST 12.4.026–76.

Upon completion of all installation work and checking their quality, the installation is presented for acceptance to the customer. Acceptance must be carried out with the participation of a representative of the fire department.
At the request of the customer, the installation can be subjected to additional tests (including fire tests) carried out according to a special program.

Installation into operation is accepted on the basis of a bilateral act. Other requirements for installation, commissioning and commissioning of installations should be taken according to the relevant regulatory documentation for water, foam and gas fire extinguishing installations, approved in the prescribed manner.

3.4. Features of the operation of powder fire extinguishing installations

During the operation of powder fire extinguishing installations, the following types of maintenance (TO) are carried out:
- daily;
- monthly;
- semi-annual;
- after the expiration date of the powder
- and once every five years.

Technical means of UPT must comply design solutions, technical documentation of manufacturers and have certificates of conformity.
After each operation of the UPT, the pipelines through which the fire extinguishing powder was supplied must be purged with compressed nitrogen.

During the daily technical inspection it is necessary:
- to carry out an external inspection to identify any damage to the installation elements;
- make sure that there are seals on the safety valve and the safety check of the start handle;
- check the presence of a cable on the rollers, the state of grounding;
- make sure that the alarm (if any) is working and that the pressure complies with the required parameters according to the readings of the pressure gauges;
- check the presence of voltage at the control panel and the condition of fire detectors in installations with electric start.

During monthly maintenance check:
- condition of fasteners, threaded connections;
- pressure in cylinders according to pressure gauges;
- performance of fire detectors.

Places with a damaged coating must be cleaned of rust, followed by the application of an anti-corrosion coating.
For semi-annual maintenance, it is necessary to perform work in the scope of monthly maintenance, as well as:
- check the value of the residual deformation of the cable and, if necessary, tighten it;
- check or technical certification pressure gauges, cylinders, vessels at the expiration of the examination period;
- check the condition and performance of the pneumatic (threshold) valve on the vessel;
- to weigh the launch cylinders.

During maintenance after the expiration date of the fire extinguishing composition, in addition to the work listed above, it is necessary to charge the powder in specialized organizations and check the connections of the distribution network.

During maintenance once every 5 years, it is necessary to carry out maintenance work and additionally inspect vessels with powder and gas cylinders with working gas in accordance with the requirements of Gosgortekhnadzor, as well as check the operation of the safety valve.

Academy of the State Fire Service of the Ministry of Emergency Situations of Russia,
Tutorial for educational institutions EMERCOM of Russia, 2007