Fire water supply- this is a system of devices for supplying water to the site of a fire in sufficient quantities and with a given pressure (Fig. 56). It includes an alluvial station that takes water from a source (well, artificial or natural reservoir), a network of pipelines and devices that ensure water delivery:

– to fire hydrants (Fig. 57), located along the external fire water supply network and intended for extinguishing buildings from the outside (external fire extinguishing);

– to fire hydrants and water supply network devices located inside buildings (internal fire water supply), intended for extinguishing fires inside buildings;

– for automatic and semi-automatic fire extinguishing systems - sprinkler (Fig. 58) and deluge (Fig. 59) networks (mainly for indoor extinguishing).

Rice. 56. Fire water supply

Rice. 57. Fire hydrant

Rice. 58. Fire sprinkler system

Rice. 59. Deluge fire extinguishing network

External fire-fighting networks, as a rule, are combined with domestic and drinking water supply (less stagnation of water in pipelines and, therefore, less corrosion and wear, greater durability; lower costs for the manufacture and installation of networks).

The parameters of the elements of a combined fire-household-drinking water supply system are calculated (power of the pumping station, pressure, volume of supplied water per unit of time, pipeline diameter, etc.) from the condition of water consumption for all these needs simultaneously according to SP 8.13130.2009 and SP 10.13130. 2009 taking into account: fire resistance of buildings (lower degree of fire resistance - higher consumption), categories of premises and buildings according to fire hazard (higher category - higher consumption), width of buildings (over 60 m - higher consumption), the number of simultaneously operating fire extinguishing jets inside the building ( for industrial buildings - from two to four jets) with a water flow rate for all jets from 5 to 100 l/s.

When calculating water consumption, the possibility of starting and extinguishing two fires at once is additionally taken into account. Two fires should be counted on if the area of ​​the enterprise is more than 150 hectares, or if the combined fire water supply (drinking-fire-service) serves not only the enterprise, but also a village with a population of over 10 thousand people.

The water supply must ensure fire extinguishing for at least 3 hours (for buildings of fire resistance degrees I and II with non-combustible load-bearing structures and fire hazard categories G and D - 2 hours, timber warehouses - 5 hours).

Fire water supply can be performed at low and high pressure.

Low pressure water supply must provide free pressure (height of a compact stream of water) at ground level of at least 10 m. Water from it is supplied to the fire site using auto pumps and motor pumps.

High pressure water supply must provide pressure for direct supply of water to the combustion zone. In this case, the height of the compact jet must be at least 20 m at full flow rate and the fire nozzle is located at the level of the highest point of the tallest building. Fire water supply systems are usually created at low pressure; high pressure - created only with appropriate justification. Increased pressure in the internal fire extinguishing water supply is created using additional pumps installed in buildings and turned on only during a fire.

The free pressure in the combined water supply network should not exceed 60 m, and the hydrostatic pressure at the lowest point of the water supply system should not exceed 0.45 MPa. Exceeding these values ​​threatens the possibility of rupture of pipes, threaded connections, shut-off and water fittings, fire hoses, and also makes it very difficult to control manual fire nozzles (the jet thrust is high, it is very difficult to hold the fire nozzle).

The external fire-fighting water supply network is usually of the ring type. It should be placed at a distance no closer than 5 m from buildings and no more than 2.5 m from the side of roads. Water intake hydrants are installed on the network in such a quantity as to ensure fire extinguishing of any building, structure, object or part thereof from at least two hydrants (if the required water flow for external fire extinguishing is 15 l/s or more) or from one hydrant (less than 15 l /s) taking into account the maximum length of the laid hose lines 100-200 m (depending on the type of fire equipment connected to the hydrant).

Fire hydrants must always be in good condition, and in winter - insulated and cleared of snow and ice. Appropriate signs (volumetric with a lamp or flat with a reflective coating, resistant to atmospheric influences) must be installed at hydrants and in the direction of movement towards them. They must be marked with numbers indicating the distance to the hydrant.

The diameter of the pipes of the combined external water supply in cities and on the territory of production facilities must be at least 100 mm, and in rural settlements - at least 75 mm.

If obtaining the estimated amount of water directly from the water supply source (well with a pumping station) is impossible or economically unfeasible, then the water supply system provides special reservoirs, artificial reservoirs (at least two), each of which must contain at least 50% of the required (calculated) volume of water.

The fire volume of water in the tanks of water towers must ensure that one fire can be extinguished outside and inside the building within 10 minutes, while simultaneously using the greatest amount of water for other needs.

The maximum period for restoring the fire volume of water should be for industrial enterprises with premises of fire hazard categories A, B, C - 24 hours, D and D - 36 hours; for settlements and agricultural enterprises - 72 hours.

Reservoirs (lakes, rivers, artificial ponds) from which water is drawn for fire fighting must be equipped with an entrance with hard-surfaced platforms (piers) measuring at least 12 ´ 12 m for installation of fire trucks on them at any time of the year.

Fire tanks or artificial ponds placed on the condition that each fire must be extinguished from at least two adjacent reservoirs, taking into account the service radius: 200 m - if water is supplied to extinguish the fire by auto pumps (fire trucks) and 100 m - by motor pumps. But these tanks should not be closer than 30 m from buildings of fire resistance degrees III and V and 10 m from buildings of fire resistance degrees I and II. Otherwise, in conditions of fire and high temperature, it will be impossible to place firefighting equipment between the tanks and burning buildings.

If it is difficult to directly draw water from a fire reservoir or reservoir using autopumps or motor pumps, receiving wells with a volume of 3-5 m 3 should be provided near them, connected to the reservoir by a pipeline with a diameter of at least 200 mm. On the pipeline itself, in front of the receiving well, a well with a valve is installed, the steering wheel from which is brought out under the manhole cover.

Internal fire extinguishing is carried out from fire hydrants installed inside buildings in the parking areas of the internal fire water supply in fire cabinets. Each fire hydrant (fire cabinet) is equipped with a fire hose 10, 15 or 20 m long and a fire nozzle. The fire hose must be connected to the valve and fire nozzle.

Fire hydrants(fire cabinets) are placed at a height of 1.35 + 0.15 m above the floor (for ease of use). Fire cabinets must have openings for ventilation and devices for sealing. It is desirable that the doors of fire cabinets have a transparent insert for visual inspection of the configuration. At least once a year, it is necessary to roll the fire hose onto a new slope to avoid damage to the hose at the bends, and check the condition of the fire hydrants at least once every six months.

Fire cabinets provide the possibility of placing hand-held fire extinguishers, means of protection and rescue of people (automatic rope release device, 2-3 self-rescuers, first aid kit, set of non-mechanized firefighting tools).

When determining the installation locations of fire hydrants (fire cabinets), it is assumed that in industrial and public buildings each point in the room should be irrigated with at least two jets: one and two adjacent risers, i.e. from two different fire cabinets, taking into account the length fire hoses used. They are installed mainly at entrances, on the landings of heated staircases, in lobbies, corridors, passages and other most accessible places. But their location should not interfere with the evacuation of people in case of fire.

On the doors of fire cabinets there are instructions on the procedure for opening them, on the contents and procedure for using the fire extinguishing means contained in them, means of protecting and rescuing people, and on the procedure for turning on the booster pump. In addition, the serial number of the fire cabinet, the abbreviation of the fire hydrant “PK”, fire safety signs indicating the fire hydrant, and fire extinguishers are applied to the outside of the door. The color of the fire cabinet is red.

If there is a constant or periodic lack of water in the internal fire-fighting water supply system, it is necessary to install fire pumping units that increase the pressure. They are located in rooms made of non-combustible materials on the first and not lower than the first underground floors of buildings of I and II degrees of fire resistance. Starting pumping units can be manual, remote (start buttons are located in cabinets near fire hydrants), or automatic.

The signal from the automatic or remote control must be sent to the fire pumping units after automatically checking the water pressure in the system. If there is sufficient pressure, the start-up should be automatically canceled until the pressure drops, requiring the pumps to be turned on. Excessive pressure increases can damage the plumbing system and the building may be left without water. The fire station room (or other room with people occupied around the clock) simultaneously with the remote or automatic activation of pumps, as well as their emergency shutdown, must receive light and sound signals to alert the personnel on duty.

Boost pumps must be provided with a power supply of increased reliability. In case of a sudden shutdown of the main source of electricity, another backup, independent source of power must be introduced. With an estimated water flow of more than 2.5 l/s, the transition to the second source should occur automatically (I reliability category), and with a water flow of up to 2.5 l/s - by manual activation or start (II category).

Regulatory documents allow the provision of natural or artificial reservoirs as sources of external fire-fighting water supply for settlements with a population of up to 5 thousand people. It is allowed not to provide fire-fighting water supply for settlements with a population of up to 50 people. when building with buildings up to two floors high, for industrial buildings of I and II degree of fire resistance with a volume of up to 1000 m 3 (except for buildings with unprotected metal or wooden load-bearing structures, as well as with polymer insulation with a volume of up to 250 m 3) with fire category D production and explosion and fire hazards, etc.

Internal fire water supply is not required to be provided in residential buildings with up to 12 floors, in administrative buildings of industrial enterprises, dormitories and public buildings with a volume of up to 5000 m 3 , office buildings with a height of up to 6 floors, in industrial and warehouse buildings with a volume of up to 2500 m 3 and some others.

4.7. Notification system
and management of evacuation of people in case of fire

Warning and evacuation management system(SOUE) is a set of measures and technical means designed to timely inform people about the occurrence of a fire, the need to evacuate, the routes and order of evacuation. This is achieved by one of the following methods or a combination of them:

1) supply of light, sound and (or) speech signals to all premises with permanent or temporary occupancy of people;

2) broadcast of specially developed texts about the need for evacuation, evacuation routes, direction of movement and other actions to ensure the safety of people and prevent panic in the event of a fire;

3) placement and lighting of fire safety signs on evacuation routes within the standard time;

4) turning on evacuation (emergency) lighting;

5) remote opening of emergency exit door locks;

6) providing communication between the fire post (control room) and fire warning zones, etc.

According to SP 3.13130.2009 “Warning and management system for evacuation of people in case of fire”, the sound level of SOUE sound annunciators must be 15 dBA higher than the standard noise level in the protected room and at least 75 dBA at a distance of 3 m from the siren, but not more than 120 dBA anywhere in the protected area.

The fire alarm system should turn on automatically when a signal is received from automatic fire alarm or fire extinguishing installations. Remote, manual, local activation of the fire alarm system may be provided if the building (structure), in accordance with regulatory requirements, is not intended to be equipped with automatic fire alarm or fire extinguishing systems.

Location of buttons for manual activation of the SOUE(“panic” buttons) should be indicated on fire evacuation plans. The instructions for these plans must contain information about who has the right to activate the panic buttons.

The procedure for the action of the security post personnel on duty when the emergency warning system is triggered must be set out in the instructions posted at the security post.

Depending on the notification method, division of the building into warning zones and other characteristics, the SOUE is divided into five types, shown in Table. 12.

Table 12. Main types of SOUE and their characteristics

Note:“+” - required; “*” - allowed; "-" - not required.

Buildings are equipped with a fire alarm system of the appropriate type in accordance with SP 3.13130.2009. For example, one-story industrial and warehouse buildings, car parks of all fire hazard categories must be equipped with fire alarm system of the 1st type, categories A, B with a number of floors from 2 to 6 - type 3, categories B with a number of floors from 2 to 8 - 2- th type, etc.

Design, installation and maintenance of SOUE are carried out by specialized organizations that have the appropriate licenses.

4.8. Automatic fire extinguishing systems
and fire alarm

Automatic fire extinguishing installations (AUP) are designed for automatic detection and extinguishing of fire in its initial stage with simultaneous giving of a fire alarm signal.

Automatic fire alarm installations (AUPS) are designed to detect a fire in its initial stage, report the location of its occurrence, and send an appropriate signal to the security post (duty post).

The current practice of designing AUP and AUPS is such that the AUP simultaneously performs the functions of an AUPS. AUP and AUPS systems protect buildings, premises in which flammable and combustible substances are stored or used, valuable equipment and raw materials, warehouses for petroleum products, varnishes, paints, book depositories, museums, electronic computer facilities, etc.

Sensors that respond to fire factors (fire, smoke, gas, increased air temperature, increased rate of growth of any factor, etc.) in AUP and AUPS systems are fire detectors (FD). PI is installed in the premises to be protected. In the event of a fire, the PI sends a signal to the fire alarm control device and to the control device. There, the signal is processed and sent to the fire department post (or to the duty personnel post), where it informs about the situation that has arisen, indicating the room and area where the PI was working.

When two or more PIs are triggered simultaneously (and they are usually placed in each room at least two), the control devices, depending on the program embedded in them: turn on the warning system and control the evacuation of people in case of fire (SOUE), turn off the power supply to the process equipment, turn on the smoke removal systems, close the doors of the room where the fire that has arisen is supposed to be extinguished with gas fire extinguishing agent, and at the same time delay the release of the fire extinguishing agent for the time during which people must leave this room, and if necessary, turn off the ventilation; in the event of a power failure, the system is transferred to a backup power source and a command is given to release the fire extinguishing agent into the combustion zone.

The choice of one or another type of PI depends on the predominant type of fire factors occurring (smoke, flame, etc.). For example, in accordance with SP 5.13130.2009, industrial buildings containing wood, synthetic resins or fibers, polymer materials, textiles, rubber products are protected with smoke and thermal PIs; premises with computer equipment, radio equipment, administrative and public buildings - smoke detectors, etc.

The number of automatic fire detectors installed in one protected room depends on the area of ​​this room, ceiling height, average area controlled by the selected PIs, the distance between PIs and the distance to the wall. For example, point smoke detectors with a height of the protected room up to 3.5 m control each area up to 85 m2, and can be installed at a distance of 9.0 m from each other, and 4.5 m from the wall.

AUP are subdivided by design:

– on sprinkler systems (see Fig. 58),

– deluge (see Fig. 59),

– sprinkler-drencher,

– modular;

by type of fire extinguishing agent used:

– water (including with finely sprayed water, drops - up to 100 microns),

– foam (including high-expansion foam),

– gas (using carbon dioxide, nitrogen, argon, various refrigerants, etc.),

– powder (modular),

– aerosol fire extinguishing,

– combined fire extinguishing.

The type of fire extinguishing and alarm installation or their combination, the extinguishing method, and the type of fire protection equipment are determined by the design organization for each facility individually. This organization must have the appropriate license to design, install and maintain such systems. The register of these organizations is maintained by the Russian Ministry of Emergency Situations. After the fire automatics installations are put into operation, the head of the organization, by his order (instruction), appoints persons responsible for their operation (usually these are employees of the departments of the chief mechanic, chief power engineer, and instrumentation service).

Daily round-the-clock monitoring of the operation of the automatic fire control system and automatic fire control system is carried out by operational duty personnel (shift service, fire station), who must know the procedure for calling the fire department, the name and location of the premises protected by fire automatic fire control systems (aumatic fire control system, automatic fire control system), the procedure for maintaining operational documentation and determining the operability of these systems .

CONCLUSION

The academic discipline “Fire Safety” is a discipline of the professional cycle in the State educational standard of higher professional education in the preparation of bachelors in the areas of undergraduate studies 03/20/01 “Technosphere Safety” and 03/18/02 “Energy and resource-saving processes in chemical technology, petrochemistry and biotechnology”. When studying this discipline, students will become familiar with the fire hazardous properties of substances and materials, classifications of fires, technological environments, building materials, buildings; learn about the fire safety system, rules and possibilities for organizing a fire safety regime at the enterprise; master the fire detection and extinguishing system. The manual will allow you to find out what means are used to extinguish fires, what elements a carbon dioxide fire extinguisher consists of and what is the principle of its operation; familiarize yourself with firefighting equipment, warning systems and evacuation management in the event of a fire.

After studying the discipline “Fire Safety”, the student must know statistical information about the occurrence of fires in the Russian Federation, the number of dead and injured people, material damage caused by fires; what a fire is and what are the conditions for its occurrence at work, at home, in the forest; classification of fire hazardous areas, technological environments, building materials and buildings for fire safety, their categorization; procedure for action in case of fire, procedure for the fire safety regime of the enterprise, liability for violation of fire safety requirements. In addition, after studying the theoretical part, the student must master the practical skills of assessing the fire hazard of production areas, premises, buildings, and territories; using different types of fire extinguishers; methods of writing instructions on fire safety measures, conducting fire safety briefings, developing schematic plans for evacuating people in case of fires, self-rescue in case of fire and rescuing other people and property.

All of the above will allow us to prepare bachelors with modern knowledge and practical skills in the field of fire safety.

SubjectFire water supply. Purpose and design of a fire hydrant and fire pump

Type of activity: class-group

Allotted time: 2 teaching hours.

Literature: textbook “Fire fighting equipment”

Detailed lesson plan.

Water supply in the system of measures ensuring fire safety

Water supply system is a complex of engineering structures designed to collect water from a water source, purify it, store it and supply it to places of consumption.

Purpose of fire water supply is to ensure the supply of the required volumes of water under the required pressure during the standard fire extinguishing time, provided that the operation of the entire complex of water supply structures is sufficiently reliable. The main regulatory requirements for water supply are set out in building codes and regulations SNiP 2.04.02-84 “Water supply. External networks and structures."

Water supply systems (pipelines) are classified according to a number of criteria:

Reliability of water supply– they are divided into three categories:

1st reliability category– enterprises of the metallurgical, oil refining, petrochemical and chemical industries, power plants; utility and drinking water supply systems of settlements with a population of more than 50,000 people - a reduction in water supply by no more than 30% of the calculated standards is allowed for up to 3 days.

2nd reliability category – enterprises of coal, mining, oil production, engineering and other types of industries; utility and drinking water supply systems in populated areas with a population of up to 50,000 people and group agricultural water supply systems - it is allowed to reduce the water supply by no more than 30% of the calculated standards for up to 1 month or interruptions in the water supply for up to 5 hours.

3-th category of reliability– small industrial enterprises; agricultural irrigation systems; utility and drinking water supply systems in settlements with a population of up to 500 people - an interruption in water supply for up to 1 day or a reduction in water supply by no more than 30% of the calculated standards for a period of up to 1 month is allowed.

By type of serviced object Water supply systems are divided into urban, settlement, as well as industrial, agricultural, railway and others.

By type of natural sources used There are water pipelines that take water from surface sources (rivers, reservoirs, lakes, seas) and underground (artesian, spring). There are also mixed supply water pipes.

According to the method of water supply There are pressure water pipes with mechanical water supply by pumps and gravity (gravity) water pipes, which are installed in mountainous areas when the water source is located at a height that provides a natural supply of water to consumers.

By purpose water supply systems are divided into household and drinking systems that satisfy the needs of the population; production processes supplying water; fire and combined. The latter are usually located in populated areas. From these same water pipelines, water is supplied to industrial enterprises if, according to the conditions of the technological production process, they require water of drinking quality. If water consumption is high, enterprises can have independent water supply systems to meet their drinking, industrial and fire-fighting needs. In this case, fire-fighting and industrial water pipelines are usually constructed. The combination of a fire water supply system with a household one, rather than an industrial one, is explained by the fact that the industrial water supply network is usually less extensive and does not cover all the volumes of the enterprise. In addition, for some production processes, water must be supplied under a strictly defined pressure, which will change when extinguishing a fire. Independent fire-fighting water supply systems are usually installed at the most fire-hazardous facilities - petrochemical and oil refining industry enterprises, oil and petroleum product warehouses, timber exchanges, liquefied gas storage facilities, etc. Fire-fighting water supply systems are of low and high pressure. In low-pressure water pipelines, the necessary pressure at the trunks is created using mobile fire pumps installed on hydrants. In high-pressure water supply systems, water is supplied to the fire site through hose lines directly from hydrants under pressure from stationary fire pumps installed in the pumping station.

Plumbed and non-plumbed. water supply, classification of external water pipelines

In accordance with the two categories of natural water sources, water intake structures are also divided into two groups: structures for receiving water from surface sources and structures for receiving groundwater. The choice of a particular source of water supply is determined by local natural conditions, sanatorium and hygienic requirements for water quality and technical and economic considerations. Where possible, preference should be given to underground water supply sources.

Surface sources include: rivers, lakes and in some cases seas. The location of the water intake is determined in such a way that the following conditions are satisfied:

the possibility of using the simplest and cheapest method of collecting water from a source;

uninterrupted receipt of the required amount of water;

ensuring the supply of the purest possible water (purification from pollution);

the closest location to the supplied facility (to reduce the cost of water pipelines and water supply).

Groundwater occurs at different depths and in different rocks.

For water supply use:

water from confined aquifers covered on top by waterproof rocks that protect groundwater from pollution;

free-surface groundwater contained in layers that do not have a waterproof roof;

spring water (spring water, i.e. underground water that independently rises to the surface of the earth);

mine and mine waters (usually for industrial water supply), i.e. groundwater entering drainage structures during mining.

Types of fire hydrants:

Moscow

Leningradsky

Rostov (Nakhichevan)

One of the mandatory conditions of systems that ensure the safety of industrial and residential buildings and structures is their constant readiness to alert people, prevent the occurrence of dangerous situations, and, if they occur, eliminate hotspots of emergencies and disasters. And if warning systems are needed only to notify people of danger, then fire water supply systems must ensure, among other things, the operability of fire equipment until the fire is completely extinguished and possible sources of re-ignition are eliminated.

The specificity of the operation of such systems is that they must be ready to operate in any conditions, regardless of the time of day, season, or ambient temperature.

Main sources of fire water supply

To properly ensure fire safety of industrial enterprises, civil facilities and residential infrastructure, fire safety systems must be designed taking into account the possible need for water as the main fire extinguishing agent. For the normal use of the system, the issue of water supply sources is important, according to which the primary classification of fire water supply systems can be carried out.

Simply put, this is a classification of water sources from where it will be supplied to extinguish a fire.

The main sources of water intake and transportation to the fire extinguishing site will be:

• Open natural reservoirs;
• Artificial water structures for general purposes;
• Special reservoirs and reservoirs in which a supply of water is created;
• Fire water supply.

The use of each of the listed sources has its own specifics and features, because in each specific case all possible options for using the source are calculated both by the entire system and its individual components, from simply pumping water into a fire truck tank to connecting to a centralized fire-fighting water supply system.

Natural sources of water - reservoirs - are used in the overall fire protection scheme of both an individual facility and entire regions. Rivers, lakes, reservoirs and even sea bays and seas are a practically inexhaustible source of water, which means that a water supply system based on the use of a natural water source is the most convenient for constructing a fire water supply system. On the other hand, to implement in practice, water intake from a river or lake requires the presence of many components - from laying water pipes with the construction of pumping stations, to equipping vehicle entrances for filling tanks. That is why such investments are not always justified and appropriate.

Artificial water structures for general purposes, which include city ponds, park lakes, reservoirs and even small reclamation wells, are used mainly as backup sources of fire water supply. The only exceptions to this list are reservoirs with a water volume of over 5,000 cubic meters. Calculation of the possibility of using such sources is carried out taking into account seasonal fluctuations in the filling level of the reservoir and the possibility of water intake in any conditions.

Special fire ponds and reservoirs are built based on the needs and requirements of enterprises, organizations, individual infrastructure facilities and residential areas. A reserve underground reservoir or a closed underground reservoir is equipped specifically for the use of water from it only for fire extinguishing, and in no case for other purposes. Such reservoirs are specially designed as part of a fire water supply system with all the necessary attributes - pumping stations, connected pipelines, access roads.

The fire-fighting water supply system is a system of specially laid high-pressure pipelines with specially equipped points of access and water intake, equipped for connecting fire extinguishing equipment. A high-pressure fire water supply system connected to a general water supply system in urban environments today is the main means of water supply for extinguishing fires.

Internal and external fire water supply systems

The design and construction of industrial facilities, office and residential buildings cannot be completed without including internal and external fire extinguishing systems in the project. In most cases, all multi-storey buildings are required to be equipped with internal fire water supply lines located inside the building, and external fire extinguishing systems are installed outside the buildings.

In essence, internal fire extinguishing systems are designed to quickly respond to fires and localize fires within the building. Internal networks in buildings, as well as regular water supply, are connected to external high-pressure water supply systems and are its continuation only inside the building.

External fire water supply systems are usually located in specialized underground caissons and are opened using special equipment to extinguish a fire outside the building or in an open area. External systems may include pumping stations for collecting water from open sources and reservoirs, filtration stations, above-ground and underground water pipelines and wells for installing fire hydrants.

The use of both internal and external water supply systems is determined by the importance of the site on which the system is located. If for multi-storey buildings an internal fire water supply system is provided with taps and hydrants on each floor, every 20 meters, then the external water supply can be designed in such a way as to ensure water supply from one hydrant to 2-3 entrances of an apartment building from the street side and from sides of the patio.

Necessary parameters of fire water supply networks

The design and construction of plumbing systems used to extinguish fires without fail is carried out taking into account the possible source of ignition and the largest volume of the fire area, both with one source of ignition and with several sources of combustion.

In this regard, standard indicators of water demand are used to extinguish fires of varying intensity, density and volume:

• Water supply in residential buildings and social infrastructure facilities is calculated based on throughput - 5 liters of water per second per connection point;
• The pressure for household fire-fighting networks must be at least 10 meters of water column;
• The guaranteed water reserve must be 250 or more liters of water per building;
• The volume of water reserve for extinguishing several objects, for example, a country or cottage village, is at least 5000 cubic meters.

To design external water supply systems for fire extinguishing systems at industrial enterprises, warehouses or open parking lots for equipment storage, there must be at least:

• The throughput capacity of the water pipeline, depending on the fire hazard category of the facility, is 60–240 liters per second;
• Warehouses and container sites - 10-20 liters per second;
• Car parking lots, car repair shops and garages - 20-50 liters per second.

When choosing a source of water supply for such systems, the volume of water reserves must be taken into account, namely the need for constant water pressure for continuous operation for 1 hour for ordinary objects, and 2.5 hours for high-risk objects.

Basic models and standard designs of facility fire water supply systems

Specific and sometimes unique construction and architectural solutions for industrial buildings, complexes and residential buildings require the same unconventional approach to solving the issues of designing a fire water supply system for each individual facility.

At the same time, despite the uniqueness and peculiarity of fire water supply facilities, there are standard solutions for the configuration of fire water supply systems, which provide for a main, auxiliary and backup water supply system.

The main water supply system may include:

• Source of water supply;
• Pumping station;
• Water tower;
• Water pipes;
• Internal fire extinguishing system;
• Network of hydrants.

Auxiliary systems may include:

• Temporary water pipelines and mains;
• Technological water pipelines of enterprises;
• City water supply systems.

Reserves include:

• Mobile pumping stations;
• Reserve reservoirs;
• Water tanks;
• Natural water sources.

Designing a fire water supply for a separate infrastructure facility, with the construction of a separate water tower, is not always rational and justified, but the use of a conventional water tower as the main volume for water is quite justified. A water tower, as part of a conventional water supply system, places a large volume of water at a sufficient height, this makes it possible to create a large pressure of water and ensure its rise to the desired height.

The water tower can be powered by pumping stations that lift water from the aquifer to the height of the upper reservoir. Pumping stations can also operate directly, supplying water to water pipes, but the volume of water must be maximum so that the water supply is not damaged.

The water supply system, consisting of underground pipelines, manholes, branches and caisson devices, is the most expensive element of any fire water supply system. Design, excavation of trenches, laying of pipelines, insulation of pipes and installation of hydrants taking into account local conditions is the most expensive component of the water supply system. On the surface, the presence of fire water supply facilities can be evidenced by installed fire hydrants or sewer hatches with the mark “PK” or “PG” and indicators - signs on the walls of buildings.

For internal fire extinguishing systems, water hydrants are equipped already connected to special connectors of fire hoses with a fire nozzle. Such fire hydrants have a high-pressure direct-flow ball valve or valve.

Construction of an individual model of a fire water supply system

For individual infrastructure facilities, for example, oil storage facilities, chemical plants, port facilities and air terminal complexes, specific water supply systems for fire extinguishing are designed. Such facilities include not only a standard water supply with a hydrant.

These may include:

• Reserve fire reservoirs,
• direct pressure stations;
• filtration stations;
• automatic fire extinguishing systems.
• Underground water storage and above ground reservoirs;
• Railway tanks.

Fire water system maintenance

Using a plumbing fire extinguishing system for its intended purpose requires that all elements of the system are not only in place, but also technically serviceable. Like any safety system, the fire water supply system must undergo timely maintenance and repair.

In practical terms, maintenance is not something particularly complicated; at the time specified by the regulations, all components and parts are checked for leaks, completeness, and each tap and hydrant is turned on for a short time. Identified malfunctions and shortcomings must be eliminated as soon as possible.

Fire water supply systems are systems in which water must meet several important criteria: be available at any time of the day and year and be in sufficient quantity to extinguish the fire. Both criteria are extremely important, because the result of extinguishing a fire directly depends on them, which means that human lives or, at best, property are at stake.

Types and classification

For convenience, we present the data in table form:

The factors by which this classification of types of water supply is carried out directly influence the result when extinguishing a fire.

Natural and artificial water supply

Natural water supply refers to access to a source of water, the origin of which does not depend on humans. This can be any body of water: river, lake, reservoir, pond or sea. The human factor in this case plays a significant role in organizing access to such a source of water supply. Access must be free and there must be a place for water collection. At first glance, this may seem like a small thing, but such an attitude is misleading.

The natural source at the point of water intake must have sufficient depth and a bottom that must be clean. In this case, much depends on natural factors, but human intervention takes place for high-quality water intake. Over the years, it may happen that the water source has dried up completely or its water level has dropped significantly. In this case, you should look for a new source of water supply and not necessarily of natural origin. You shouldn't neglect your search.

Artificial water supply is represented by water pipelines and fire tank systems. If the construction of a house and the supply of a fire water supply to it was carried out according to certain rules and regulations, then it fully complies with all the necessary provisions.

According to building codes and regulations, the fire water supply must be:

• for residential buildings whose height ranges from 12 floors;
• for administrative buildings of 6 floors and above;
• in all dormitories and public buildings without exception, regardless of their number of floors;
• for administrative and industrial buildings with a volume of 5,000 cubic meters or more;
• at conference halls, cinemas, clubs, assembly halls, which are equipped with film equipment;
• in almost all production and warehouse premises without exception.

External and internal water supply

The name makes it clear where the source of water for fire extinguishing is located. It remains only to find out which water supply is more efficient in this case. Practice shows that for better fire extinguishing and minimizing the consequences of a fire, both types will prove themselves properly. However, there are small nuances. A building that is large in volume and, accordingly, in number of floors, must be provided with both types of water supply. The only exception may be small buildings that have a small number of storeys and/or a small volume.

Internal water supply is represented by fire hydrants. They should be placed in easily accessible places. Usually these are corridor exits, lobbies, staircase landings, provided that they are heated, in the corridors themselves, if their length exceeds 20 meters. Regulatory acts provide for the same length of the fire hose located inside the PC, and the same diameter of the valve and fire hose lock.

High and low pressure water supply

Low-pressure water pipelines must supply water with a stream with a water output of at least 2.5 l/s and a stream of at least 10 meters. High-pressure water supply has a more complex system: no later than 5 minutes after a fire is reported, pumps must be turned on to create the necessary pressure in the system for effective water pressure.

The choice of whether the fire water supply system will be high or low pressure depends on the design of the building. Below is a table that will help you understand the condition of fire water pipelines based on the water consumption required for fire extinguishing:

Water towers

Separately, we should consider water towers - a type of reservoir for water intended for extinguishing fires. The water towers themselves regulate the pressure and flow of water in the water supply network. According to SNiP, their installation is carried out in such a way that they begin and end the water supply network. Any water tower consists of a support shaft and a reservoir. To prevent the water in it from freezing, the water tower must be protected by a tent.

Otherwise, in sub-zero temperatures, water will freeze and expand the walls of the tank or support, causing water to leak. The height of water towers depends on the terrain and usually ranges from 10 to 45 meters. The volume of the tower changes accordingly: from several cubic meters to tens of thousands of cubic meters of water.

One type of water tower is a water tank. Their purpose: to store such an amount of water that would be sufficient to effectively extinguish a fire at a certain object for at least 2.5 hours.

Both water towers and water reservoirs are equipped with special measuring instruments to monitor the water level in them.

Fire hydrants

A hydrant is a device for drawing water when extinguishing fires. Depending on the location, fire hydrants can be used either to connect a fire hose or to supply water to a fire truck.

There are underground and above-ground hydrants. The underground hydrant must be located below ground level in a specially equipped manhole cover, but at the same time have free access to it. That is, it should not be covered by anything, and nothing should prevent the connection of the fire hose. An above-ground hydrant is installed above ground level and is a column with an installation head. The head has a thread or a special lock for quick connection of a fire hose.

Pumping stations

To force water through the system and to create the required pressure and pressure, there are pumping stations - also one of the components of the entire water supply system in case of fires.

Typically, a pumping station is a room in which pumps are located (their number depends on the water supply system), power supply systems and pipelines that set the direction from the pumping station.

The pumps are equipped with pressure gauges (to measure the pressure that the pump creates) and pressure and vacuum gauges (to measure the vacuum when drawing water). The location of pumps, pipelines, electrical panels and other structures at the pumping station should be such as not to impede free access to them, ensure normal functioning, as well as expand the area of ​​the pumping station in the future.

The operating diagram of the pumping station must be designed in such a way that in the event of a fire it is possible to respond instantly. The second feature of each pumping station is the ability to absorb water intended for household needs. This allows you to cope with a fire if there is a noticeable lack of water in the fire-fighting system.

Typically, pumping stations are organized either in the basements of buildings or independently from them. Since pumping stations are powered from a high voltage network, much attention is paid to safety when working at the station, as well as during emergency situations. Water and electricity in combination are not exactly good friends for humans.

Alarm and automatic water supply operation

The human factor in the operation of a fire protection system, as practice shows, is not reliable enough. Automation that has been properly tested and confirmed by regulatory documents is more reliable. Which can ensure the necessary uninterrupted operation of any of the system elements. Water flow, pressure control, temperature control, voltage control in the electrical power system, various types of protection, as well as a warning system - all this should be carried out automatically.

Composition of the fire cabinet kit

The emergency alarm is used to provide light and/or sound notification of the occurrence of a fire, the start of operation of one of the elements of the fire protection system, or breakdowns during the operation of the system. Signals must be sent to a fire station or another place where service personnel are available 24/7. At the same time, the sound signals have differences in their tonality, depending on what the duty officer needs to be warned about.

Conclusion

Over many years of firefighting practice, it has been repeatedly proven that relying only on the fire service is not enough. Elimination of fires must begin immediately after their detection, and for this, the serviceability of the entire water supply system plays an extremely important role. Planning during construction, operation and control over the operation of the water supply system are the main criteria on which not only the safety of property, but also human lives depend.