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 premises.

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

Characteristics of SOUE	Availability of the specified characteristics in various types of SOUE
Notification method
sound (siren, tinted signal, etc.)	+	+	*	*	*
speech (transmission of special texts)	-	-	+	+	+
light
a) flashing light alarms;	*	*	*	*	*
b) light annunciators “Exit”	*	+	+	+	+
d) light annunciators indicating the direction of movement of people, with a changing semantic meaning	-	-	-	*	+
Dividing the building into fire warning zones	-	-	*	+	+
Feedback of fire warning zones to the fire post premises - control room	-	-	*	+	+
Possibility of implementing several evacuation options from each fire warning zone	-	-	-	*	+
Coordinated control from one fire control room post of all building systems related to ensuring the safety of people in case of fire	-	-	-	-	+

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.

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Fire water supply

A water supply system is a complex of engineering structures designed to collect water from natural sources, lift it to a height, purify it (if necessary), store water reserves and supply it to places of consumption.

According to their purpose, water supply systems are divided into household and drinking water systems, intended to supply water for the household needs of the population; production processes supplying water; fire protection, providing water supply for extinguishing fires. Often combined water supply systems are installed: utility and fire, industrial and fire.

Fire water supply consists of providing protected regions, facilities, etc. necessary water flows under the required pressure during the standard fire extinguishing time while ensuring sufficient reliability of the entire complex of water supply structures.

Fire water pipelines (separate or combined) are of low and high pressure. In low-pressure water supply systems, the minimum free water pressure at ground level should be 10 m (100 kPa), and the water pressure required for fire extinguishing is created by mobile fire pumps installed on hydrants. In high-pressure water pipelines, water is supplied to the fire site directly from hydrants through fire hoses. The latter are very rarely suitable, since they require additional costs for the installation of a special pumping system and the use of increased strength pipelines. High pressure systems are provided at industrial enterprises located 2 km away from fire stations, as well as in populated areas with a population of up to 50 thousand people.

In addition, fire water supply is divided into external (outside buildings) and internal (inside buildings) fire extinguishing systems.

Fire-fighting water supply and its technical characteristics

Fire water supply (external and internal) is one of the most important elements of the fire water supply system. The design of fire-fighting water supply is carried out in accordance with SNiP 2.04.02-84 “Water supply. External networks and structures" and SNiP 2.04.01-85 "Internal water supply and sewerage of buildings." To draw water from the external water supply, fire hydrants are installed on it at a distance of 100-150 m.

As a rule, the fire-fighting water supply network is made ring-shaped, thereby ensuring high reliability of water supply. Moreover, for each ring network two inputs are made (places of connection to the previous network). Dead-end networks, i.e. a branched network in which there is only one path from each network node to the water supply point can be used in the following cases:

• for production needs, when the technology allows interruptions in water supply during the liquidation of an accident;
• for household and drinking needs with a pipe diameter of no more than 100 mm;
• for economic and fire-fighting needs with a line length of no more than 200 m, as well as in populated areas with a population of up to 5 thousand people and external fire extinguishing costs of up to 10 l/s, subject to the installation of fire-fighting tanks or reservoirs.

The diameter of the network pipes is determined by calculation taking into account the required water flow and the hydraulic resistance of all sections of the networks. Moreover, the minimum diameter of integrated water supply pipes in populated areas and industrial facilities must be at least 100 mm, and in rural areas - at least 75 mm.

When drawing water from fire truck pumps, it is necessary to know the water yield of water supply networks, which is presented in Table. 12.1 (T – dead-end network, K – ring network).

Table 12.1.

Water yield of the water supply network

Pressure in network, MPa	View networks	Diameter of water supply network pipes, mm Water yield of the water supply network, l/s
		100	125	150	200	250	300	350
0,10	T	10	20	25	30	40	55	65
	TO	25	40	55	65	85	115	130
0,20	T	14	25	30	45	55	80	90
	TO	30	60	70	90	115	170	195
0,30	T	17	35	40	55	70	95	110
	TO	40	70	80	110	145	205	235
0,40	T	21	40	45	60	80	110	140
	TO	45	85	95	130	185	235	280
0,50	T	24	45	50	70	90	120	160
	TO	50	90	105	145	200	265	325
0,60	T	26	47	55	80	110	140	190
	TO	52	95	110	163	225	290	380
0,70	T	29	50	65	90	125	160	210
	TO	58	105	130	183	255	330	440
0,80	T	32	55	70	100	140	180	250
	TO	64	115	140	205	287	370	500

Internal fire-fighting water supply systems are arranged according to the following schemes:

• without booster installations, when the water pressure from the external water supply exceeds the required water pressure;
• with fire pumps - boosters, which turn on only in case of fire and provide the required water pressure;
• with a water tank or pneumatic tank and pumps in cases where the guaranteed pressure is less than that required for household appliances and fire hydrants, ensuring an emergency fire reserve for the first 10 minutes of fire extinguishing;
• with a spare tank, when at certain times of the day there is a shortage of water or a guaranteed pressure of less than 5 m.

Internal fire-fighting water supply systems include the following elements: entry into the building, water metering unit for metering water consumption, main and distribution pipelines, water fittings and fire hydrants, pumping stations with pneumatic or open water tanks. When the number of fire hydrants in a building is no more than 12, it is allowed to use a dead-end system with one input, and when the number of hydrants is more than 12, only a ring system (or with looped inputs) with at least two inputs is allowed. Fire hydrants must be installed at a height of 1.35 m above the floor of the room and placed in cabinets, which must be equipped with a fire hose of the same diameter as the hydrant and a length of 10 to 20 m, as well as a fire nozzle. In residential buildings, fire hydrants are usually installed on staircase landings. The diameter of the valve at a flow rate of one fire jet of 4 l/s should be 50 mm, and at a higher flow rate - 65 mm.

In buildings above 9 floors, the water supply network is equipped with twin fire hydrants.

The most important element in the calculation of fire-fighting water supply systems is the determination of the water flow required for fire extinguishing. The total estimated water consumption consists of the costs for external fire extinguishing from hydrants, internal - from fire hydrants, as well as from stationary fire extinguishing installations. This flow rate with a combined water supply must be ensured at the highest water consumption for other needs of a populated area or industrial facility (excluding watering the territory, taking a shower, washing floors, washing equipment).

When rationing water consumption for external fire extinguishing, they are based on the possible number of simultaneous fires in a populated area that occur within 3 adjacent hours, depending on the number of residents and the number of storeys of buildings (SNiP 2.04.02-84). For example, for a point with a population of up to 50 thousand people, the number of simultaneous fires is assumed to be two, and with the number of floors up to two, the rate of water consumption for external fire extinguishing is 20 l/s. For industrial facilities, the number of simultaneous fires is assumed to be one for an enterprise area of ​​up to 150 hectares and two for an area of ​​more than 150 hectares. The calculated water consumption for external fire extinguishing through hydrants for one fire at an industrial enterprise is taken depending on the category of explosion hazard, degree of fire resistance, volume and design features of buildings. For example, for buildings of I and II degrees of fire resistance of categories A, B and C with a volume of up to 20 thousand m3 and a width of up to 60 m, the standard water consumption is 20 l/s. The water supply for fire extinguishing should ensure the standard water consumption for 3 hours and only for buildings of I and II degrees of fire resistance categories G and D - for 2 hours.

In some cases, non-pipeline fire-fighting water supply is allowed if there are natural (rivers, lakes) or artificial (ponds, reservoirs, reservoirs) water sources at distances of up to 500 m. Water intake for fire extinguishing can be carried out by motor pumps, auto pumps or stationary pumps with subsequent water supply through hoses. Such water supply is allowed for industrial buildings of categories B, D and D with water consumption for external extinguishing up to 10 l/s, as well as for settlements with a population of up to 5 thousand people. Moreover, the capacity of the reservoirs should provide a supply of water for extinguishing for 3 hours.

The installation of a fire-fighting water supply at construction sites must be provided before the start of the main construction work. Fire-fighting water supply in new buildings should be provided using hydrants on the water supply network or from reservoirs equipped with devices (pier, etc.) for access by fire trucks.

Internal water supply and automatic fire extinguishing systems provided for by SNiP 2.04.09-84 must be installed simultaneously with the construction of the facility.

The need to install internal water supply in buildings and premises is determined by their purpose, number of floors, height, volume. In particular, in residential buildings, the installation of internal fire-fighting water supply should be provided for the number of floors 12 and above, in dormitories over 10 floors, etc.

Construction and use of a fire hydrant and standpipe

Fire hydrants are designed to take water from the water supply network for fire needs. Fire hydrants are either underground or above ground.

Several types of fire hydrants are used on water supply networks, the most widespread of which is the underground hydrant of the Moscow type PG-5 (Fig. 12.1). The hydrant has a shutter in the form of a ball hollow valve. In the middle part there is a rubber sealing ring, which, in the closed position of the hydrants, is pressed tightly against the seat and shuts off the water supply. A small hole at the bottom of the housing is designed to drain water from the hydrant after it has been in use. When the rod, which is connected by a coupling to the spindle, rotates, the unloading valve opens. Water through it fills the internal space of the hydrant body and column. With further rotation, the ball valve opens.

Fig. 12.1 Moscow type hydrant PG-5

1 - body; 2 - cover; 3 - rod; 4 - spindle; 5 - shutter (valve)

The GOST 8220-62 hydrant (Fig. 12.2) consists of a cast iron body, a valve with a streamlined valve, a coupling spindle, a rod and a nipple closed with a lid.

An important characteristic is the amount of water hammer that occurs when opening and closing a hydrant. To prevent hydraulic shocks, a streamlined valve is located in the hydrant shut-off unit, which eliminates the possibility of stall cavitation.

The hydrant unloading valve is missing. To reduce the effort when opening a hydrant, the spindle thread pitch has been reduced by 2.5 times. There is no danger of water freezing.

Rice. 12.2. Underground fire hydrant

Underground hydrants (Fig. 12.3) are installed in water wells so that the distance between them does not exceed 150 m and that they are located no closer than 5 m from the walls of buildings. The greatest distance from hydrants to the buildings they serve should not exceed 150 m for low-pressure fire water supply systems.

Fig. 12.3 Installation of an underground fire hydrant in a water well (1 - hydrant; 2 - brackets; 3 - water supply)

Water supply lines with fire hydrants are located along driveways no further than 2.5 m from the edge of the roadway.

Hydrants are not installed on water lines with a diameter of more than 500 mm due to the complexity of installing wells. In these cases, accompanying lines of smaller diameter are sometimes laid, on which hydrants are installed. Fire pumps are used to draw water from underground hydrants for fire extinguishing (Fig. 12.4). The fire stand consists of a riser, in the lower part of which there is a threaded connection intended for connection to a hydrant, and a housing with two pipes equipped with connecting heads for connecting fire hoses. The openings of the pipes are closed with gates. Inside the column there is a tubular key with a coupling, which is designed to connect to the hydrant rod when opening and closing its shutter.

INSPECTION AND MAINTENANCE OF FIRE-FIGHTING WATER SUPPLY SYSTEMS

1. General provisions
2. General provisions

To ensure the constant readiness of fire water supply sources and their successful use in fires, the following basic activities must be carried out:

• systematic monitoring of the condition of water supply sources;
• timely preparation of fire-fighting water supply for operating conditions in the spring-summer and autumn-winter periods;
• testing water supply networks for water loss and drawing up reports based on water loss data;
• accurate accounting of all fire water supplies;
• establishing operational relationships with water supply services of the city, districts and facilities;

Together with the water supply service of the city, districts (facilities), instructions are being developed for the maintenance and operation of fire hydrants on the water supply network, which regulate the interaction of the State Fire Service and Vodokanal departments.

Control over the implementation of the listed preparatory activities is assigned to the heads of the State Fire Service (OGFS) and fire departments (FC).

Responsibility for the state of the fire water supply rests with:

• in the OGPS for the deputy chief of the OGPS for service;
• in the PCH - to the chief of guard responsible for fire water supply;
• inspection staff of the State Fire Department assigned to the facilities;

Those responsible for fire water supply are obliged to:

• keep strict records of the presence (checking) of GHGs and other sources of fire-fighting water supply in standard logs;
• monthly submit to SPT TsUS all necessary information about changes in fire-fighting water supply (installation of steam generators, replacement of steam generators, liquidation or new construction of piers, reservoirs, equipment of entrances to water supply sources, etc.);
• inform the organization in the territory where the fire control centers and the management of fire departments are located about the progress and quality of inspections of fire water supply sources;
• know the state of fire water supply in the serviced area (facility). All changes about the state of water supply sources in the area where the unit departs are entered into a log, with the obligatory familiarization of the responsible persons on guard;
• adjust tablets, plan maps and the list of fire water supply after each inspection with the start-up of water, the introduction of new ones, the dismantling of old SGs and PVs, but at least twice a year;
• monitor the timely repair of faulty hydrants and other sources of fire-fighting water supply, take measures to quickly eliminate discovered faults;

Immediately report all types of use of water supply sources during fires, exercises, PTZ, refueling to the district (facility) water supply and sewerage services (for carrying out a preventive inspection);

If a SG malfunction is detected, a bilateral report is drawn up with a representative of the water supply and utilities sector, indicating the malfunction. Information about a faulty SG is entered into a log and its repair is monitored;

All work on servicing SGs installed on the city water supply network: timely repairs, warming up frozen hydrants, pumping water from risers and wells (when using SGs in winter), providing hydrants with coordinate plates, etc., are carried out by workers of the district water and wastewater services based on the “Rules for the technical operation of systems and structures of municipal water supply and sewerage” No. 168 of December 30, 1999.

Based on the above rules, clause 2.10.12. Fire hydrants must be repaired within 24 hours from the moment the malfunction is discovered. The water supply and sewer service must notify the State Fire Service units of the detected malfunction and the completion of the repair of the hydrant.

Work to maintain hydrants on facility networks, reservoirs, piers, and entrances in working condition is carried out by the organizations that own them.

Temporary shutdowns of sections of the water supply network with fire hydrants installed on them, as well as a decrease in pressure in the network below the required one, are allowed in exceptional cases and only when developing compensatory measures agreed with the territorial fire protection authorities.

Water supply and utility services are required to notify the territorial bodies of the State Fire Service in advance of all cases of partial or complete interruption of water supply at facilities with external or internal fire-fighting water supply networks, but if fires occur at disconnected facilities, water supply and sewer services are required to immediately resume the water supply to ensure fire extinguishing.

Together with the municipal unitary enterprise Vodokanal, instructions for the maintenance and operation of fire hydrants on the water supply network must be developed and approved.

Requirements for commissioning new sources of fire-fighting water supply

To fire hydrants:

Fire hydrants are installed on ring water supply networks. Installation of SGs on dead-end lines is allowed, provided that their length does not exceed 200 meters (clause 8.16 of SNiP 2.04.02-84).

The diameter of the water supply pipes on which SGs are installed must be at least 100 mm, and the maximum – 400 mm.

Fire hydrants should be located along highways at a distance of no more than 2.5 m from the edge of the roadway, but no closer than 5 meters from the walls of buildings. It is allowed to locate the PG on the roadway. The distance between GHGs should not exceed 150 m.

Around the hatches of PG wells located in built-up areas without road surfaces or in a green zone, blind areas 1 m wide should be provided with a slope from the hatches. The blind areas should be 0.05 m higher than the adjacent territory

There must be a free entrance to the GHG with a width of at least 3.5 m.

To facilitate the search for SGs in case of fire, Vodokanal is obliged to equip SGs with signs that meet the requirements of NPB 160-97 “Signal colors. Fire safety signs. Types, sizes, general technical requirements" table. 3 clause 20, which indicate the distances to the GHG. Fire hydrant signs are usually installed on the facade of the nearest building opposite the well or close to it in a visible place.

The distance from the top of the steam generator to the top edge of the hatch should be no more than 400 mm and no less than 150 mm. The technical condition of the SG is checked by installing a column with mandatory water supply, and there should be no water leakage in the hydrant flange connections.

After the SG is put into operation and tested for water loss, a report is drawn up in triplicate, one copy each for the fire department, Vodokanal and the organization that carried out the work. Based on the acts, fire hydrants are registered, changes are made to district plan maps, water supply source boards and fire water supply lists.

To fire reservoirs (reservoirs):

The need for a device and the required volume of fire reservoirs (FW) for objects are determined by water consumption standards, with an estimated fire extinguishing time in accordance with the instructions of paragraphs. 2.16–2.18 SNiP 2.04.02-84.

The number of fire protection units must be at least two, and half the volume of water for fire extinguishing must be stored in each reservoir.

The distance from reservoirs to buildings of III, IV and V degrees of fire resistance and to open warehouses of combustible materials must be at least 30 m, to buildings of I–II degrees of fire resistance - at least 10 m; to tank farms with storage of petroleum products at least 40 m.

If it is difficult to draw water from the PV, it is necessary to provide receiving wells (dry) with a volume of 3–5 m3, connected to the PV pipe with a diameter of at least 200 mm. In front of the receiving well, a well with a valve should be installed on the connecting pipeline, the steering wheel of which should be located under the manhole cover.

Water must be drawn from each reservoir by at least two fire pumps, preferably from different sides.

Driveways with turning areas for fire trucks, no less than 12x12 m in size, are arranged to fire reservoirs and receiving wells.

For reliable water intake from natural reservoirs with steep bank slopes, as well as significant seasonal fluctuations in water horizons, entrances (piers) are built that can withstand the load of fire trucks. The access area (pier) should be located no higher than 5 m from the low water horizon and no less than 0.7 m above the high water horizon and be equipped with outlet trays for suction hoses.

The depth of the water, taking into account freezing in winter, must be at least 1 m, otherwise a pit (pit) is built at the intake site. The width of the platform flooring must be at least

4.5–5 m with a slope towards the shore and have a strong side fence 0.7–0.8 m high. At a distance of 1.5 m from the longitudinal edge of the site, a thrust beam with a cross-section of at least 25 × 25 cm is laid and strengthened.

Water loss test of water supply networks

A scheduled test of the water supply network is carried out once a year, in the spring (areas are determined jointly with the State Border Service), as well as after major repairs and the acceptance of new water supply networks.

Testing of water supply networks for water yield of individual sections of the water supply network, in accordance with the “Rules for the technical operation of public water supply systems”, clause 2.10.2. (b), approved by order of the State Construction Committee dated December 30, 1999 No. 168, is carried out by the Vodokanal divisions together with the State Fire Service with the drawing up of an act.

The following sections of the water supply network should be tested first:

• – with low blood pressure;
• – with small diameter pipes (75; 100 mm), item 8. 46 SNiP 2.04.02-84;
• – dead-end lines;
• – old lines;
• – long lines;
• – the lines most distant from the pumping stations;
• – lines with high water consumption;
• – areas near the most fire and explosion hazardous production facilities;
• – newly paved sections;
• – areas where repair work was carried out.

When testing water supply networks on the territory of which there are fire-hazardous objects and objects with large numbers of people, it is necessary to take into account the estimated amount of water for fire extinguishing purposes for these objects.

Based on the conclusions reflected in the reports, Vodokanal and the State Fire Service units, if there is a lack of water, develop measures to provide water to extinguish possible fires.

Water supply networks are tested during hours of maximum water consumption, for example, in residential buildings from 7 to 9 am, at industrial facilities with a drinking water supply - during the lunch break, with industrial and fire water supply - depending on the water consumption for the production process.

The method of testing water supply networks for water loss is to: establish the pressure and water flow available in the water supply network; determine what the water pressure and flow rate should be according to standards; compare the available pressure and make a conclusion about their compliance.

The standard water consumption for external fire extinguishing is determined on the basis of SNiP 2.04.02-84 clauses 2.4–2.26, table. No. 5–8 or calculated water flow according to the operational fire extinguishing plan option.

Testing for water loss of low-pressure water pipes is carried out using fire-fighting tankers or water supply and sewerage equipment equipped for these purposes in the following sequence:

1) the estimated fire water flow rate is determined in accordance with the requirements of SNiP 2.04.02-84 for a section of the water supply network or the estimated flow rate according to the version of the operational fire extinguishing plan;

2) the number of ACs for selecting the required water flow from the external network is determined, for example:

Qnorm. = 90 (l/sec), for testing you will need n = 90/40 = 3 pumps of the PN-40U brand (rounded up);

3) fire pumps are installed on the most unfavorably located hydrants and connected to the pump using soft hoses (to prevent pumping out water under vacuum and thereby prevent contamination of the water supply with groundwater). Sleeves with a diameter of 66.77 mm are attached to the pressure pipes of the pump (one for each pipe), ending in a barrel with large diameter sprays;

4) when testing (measuring) using a fire column, it is necessary to first calibrate it, i.e., determine the water flow depending on the pressure gauge reading. The fire pump is equipped with a pressure gauge and a drain pipe. This method is used, as a rule, in certain sections of the city water supply network.

5) the water flow from the trunks is determined and the total water flow is calculated according to the table. 2:

Table No. 2

Nozzle diameter, mm	Head at the barrel, m	Water consumption, l/sec
13	40	3,7
19	40	7,8
22	40	10,6
25	40	13,9
28	40	17,2
32	40	22,5
38	40	31,7

Fire water supply inspections

Fire water supply inspections are divided into two types: inspection No. 1 and No. 2.

Check No. 1 is carried out by external inspection (presence of a sign, condition of the entrance, presence and condition of the outer cover of the SG, internal condition of the SG well, depth of the reservoir):

• facilities security units on a monthly basis;
• city ​​fire extinguishers during the conduct of vocational technical training, PTZ development of operational plans and operational fire extinguishing cards.

Inspection No. 2 is carried out by a commission appointed by order of the head of the fire department, consisting of those responsible for the fire water supply of the fire department, representatives of the areas where the water supply network is operated.

Inspections are carried out twice a year in April–May and September–October to ensure that all water supply sources are fully operational.

Check No. 2 consists of checking:

• fulfillment of the requirements of check No. 1;
• availability of water and pressure by installing fire pumps on all SGs with mandatory water supply;
• gravity wells and water supply by installing pumps with water intake and release;
• condition of entrances, compliance of coordinates on installed signs, compliance with the requirements of SNiP 2.04.02-84.

The results of inspection No. 2 are documented in a consolidated report, drawn up in triplicate: to the fire department, to the representative of the Vodokanal water utility and to the SPT TsUS.

At temperatures from 0 to –20 °C, only external inspection of the steam generator is allowed; starting water is prohibited. At temperatures below –20 °C, in order to avoid heat loss from the well itself, it is forbidden to open the well cover.

Test method for internal fire-fighting water supply

There is no standard method for testing internal fire water pipes for water loss. FGU VNIIPO EMERCOM of Russia

To measure pressure, an insert with a pressure gauge, equipped with GMV heads, placed between the fire hydrant and the barrel, can be used. The pressure measured at the fire nozzle must be no less than the pressure at the fire hydrant given in table. 3 adj. 2. When measuring pressure at a fire hydrant, the pressure at the barrel is calculated taking into account losses along the length of the hose. When measuring pressure, the stream from the fire nozzle can be directed onto the street or, if this is unacceptable for some reason, into a special tank with a capacity of up to 100 liters.

Internal fire-fighting water supply systems must be checked for water loss on each riser on a “dictating” fire hydrant. During testing, the number of fire nozzles required by SNiP 2.04.01-85* must be switched on simultaneously. All these simultaneously working trunks are “dictating”. Tests should be carried out during the period of the day when the greatest amount of water is collected.

All other faucets that are not subjected to fluid loss tests must be tested for opening and closing twice a year. Before this, the fire hydrant valve must be freed from the fire hose, and a plug with a pressure gauge attached to the valve connecting nut must be attached. After this, the fire valve locking device must be turned from one extreme position to the other at least 5 times.

Control and organization of fire safety water supply inspections

For a qualitative study and control over the state of fire-fighting water supply, the departure area of ​​the unit (facility) is divided into sections. The water supply to these areas is assigned to guards for a period of no more than 2 years.

On guard duty, unit orders appoint persons responsible for fire-fighting water supply to the departure area. The assignment of areas for checking fire-fighting water supply to guard posts is formalized by order. Responsible persons, annually, when summing up the results of combat training, take tests on knowledge of fire-fighting water supply.

Responsibility for the state of the facility's fire-fighting water supply rests with the inspection staff of the State Fire Department assigned to these facilities.

The results of checks No. 1, 2 are recorded in the fire-fighting water supply inspection logs and the list of water supply sources at the fire control center.

The results of inspection No. 2 are documented in a consolidated report, drawn up in triplicate: to a representative of the fire department, a representative of the Vodokanal water utility, and to the SPT TsUS.

Information on the state of fire-fighting water supply in the protected area is submitted monthly to the SPT NCC.

Based on the results of the spring (autumn) inspection, the list of water supply sources on the PSCH in the water supply tablets and the list of waterless areas are adjusted.

Based on the results of fire-fighting water supply inspections, orders are issued to the managers of Vodokanal (facilities), copies of the orders are provided to the SPT TsUS. In case of failure to comply with the order within the established time frame, administrative practices are applied to the above-mentioned managers.

Based on the results of the spring and autumn inspections of the fire-fighting water supply, a letter is drawn up to the head of the district administration, which reflects the shortcomings of the fire-fighting water supply and raises questions about how to eliminate them as soon as possible.

Based on the results of inspection No. 2, a schedule for repair and replacement of steam generators is developed, taking into account the importance of the location of the steam generators requiring repair and the technical capabilities of Vodokanal, which are approved by the district administration, the timing is determined only in the summer and no more than one month.

Accounting for work and requests for repairs of water supply sources is kept in a log on the PSCh.

An inspection of a facility's water supply is carried out similarly to an inspection of a city's water supply in the presence of a representative of the facility and the inspector to whom the facility is assigned, or by the inspector in person.

Acts of inspection of water supply sections for water loss are stored in the fire-fighting water supply supervision file of the exit area, copies are sent to the SPT Central Control Center.

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

The 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 figure shows a general diagram of the city's water supply

1- water intake; 2 - gravity pipe; 3 - coastal well; 4 — pumps of the first lift; 5 - settling tanks; 6 - filters; 7 - spare clean water tanks; 5 - pumps II lift 9 - water pipelines; 10- pressure control structure; 11 — main pipes; 12 — distribution pipes; 13 - house inputs; 14 - consumers.

Construction of a water tower or other pressure control structures is often necessary if there is significant unevenness in the city’s water consumption by hour of the day and its supply by lift pumps II. Pressure control structures are intended to store a supply of water for fire extinguishing.

The task of the water supply system of an industrial enterprise is to provide it with water for industrial, drinking and fire-fighting needs.

1 - water intake structure; 2 - pumping station; 3.8 - treatment facilities; 4 - independent network; 5 - network; 6 - sewer network; 7 - workshops; 9 - village

Pumping station 2 , located near the water intake structure 1 , supplies water for production purposes to workshops 7 over the network 5 . Waste water flows through the sewer network 6 into the same body of water without treatment (if it is not polluted) or, if necessary, after cleaning it in a treatment facility 8 . If it is necessary to supply water for industrial needs at different pressures, several groups of pumps are installed at the pumping station, feeding separate networks. Day of economic and fire safety needs of the village 9 and workshops of the enterprise 7 water is supplied to a separate network 4 special pumps. The water is pre-purified in treatment facilities 3 .

1 - water intake; 2.5 - pumps; 3 - water conduits; 4 – cooling structures; 6.8- pipelines; 7 - production units.

Pumps 5 supply water after cooling in structure 4 through pipelines 6 to production units 7. Heated water enters pipelines 8 and is discharged to cooling structures 4 (cooling towers, spray pools, cooling ponds). The addition of fresh water from the source through the water intake 1 is carried out by pumps 2 through water pipelines 3. The amount of fresh water in such systems is usually a small part (3-6%) of the total amount of water.

Classification of external water pipelines

Waterless PV based on water intake from natural or artificial fire reservoirs. For this purpose, platforms are set up on the shore to place fire pumps, and sometimes water intake devices.

Tap water supply - based on water intake from fire hydrants in a ring or dead-end network.

By type of serviced object

According to the method of water supply

Pressure water pipelines are those in which water is supplied from the source to the consumer by pumps

They are called gravity , in which water from a high-lying source flows to the consumer by gravity. Such water pipelines are sometimes installed in mountainous regions of the country.

Scheme of gravity water supply: 1 - water intake; 2 - gravity-flow structures; 3 - coastal well and treatment facilities; 4 - unloading well; 5 - unloading tank; 6 - water supply; 7 - water supply network

Requirements for fire-fighting water supply sources

Buildings, structures and structures, as well as the territories of organizations and populated areas, must have sources of fire-fighting water supply for extinguishing fires.

Natural and artificial reservoirs, as well as internal and external water supply systems (including drinking, domestic, utility and fire-fighting) can be used as sources of fire-fighting water supply. The need for the construction of artificial reservoirs, the use of natural reservoirs and the installation of fire-fighting water supply systems, as well as their parameters, are determined by this Federal Law.

In the territories of settlements and urban districts there must be sources of external or internal fire-fighting water supply. Settlements and urban districts must be equipped with fire-fighting water supply. In this case, the fire-fighting water supply system may be combined with drinking water supply or industrial water supply systems.

Sources of external fire-fighting water supply include:

• external water supply networks with fire hydrants;
• water bodies used for fire extinguishing purposes in accordance with the legislation of the Russian Federation.

In settlements and urban districts with a population of up to 5,000 people, detached public buildings with a volume of up to 1,000 cubic meters, located in settlements and urban districts that do not have a ring fire water supply, industrial buildings with production categories B, D and D for fire and explosion hazards and fire hazards with a water consumption for external fire extinguishing of 10 liters per second, in roughage warehouses with a volume of up to 1000 cubic meters, mineral fertilizer warehouses with a volume of up to 5000 cubic meters, in buildings of radio and television transmitting stations, buildings of refrigerators and storages of vegetables and fruits, it is allowed to provide external fire extinguishing sources as sources water supply from natural or artificial reservoirs.

Water consumption for external fire extinguishing of one- and two-story production facilities and one-story warehouse buildings with a height of no more than 18 meters with load-bearing steel structures and enclosing structures made of profiled steel or asbestos-cement sheets with combustible or polymer insulation should be taken at 10 liters per second .

In high-pressure water supply, stationary fire pumps must be equipped with devices that ensure starting of the pumps no later than 5 minutes after giving a signal about a fire.

The minimum free pressure in the low-pressure fire-fighting water supply network during fire fighting should be at least 10 meters.

The minimum free pressure in the high-pressure fire-fighting water supply network must ensure the height of the compact jet at least 20 meters with full water consumption for fire extinguishing and the location of the fire trunk at the level of the highest point of the tallest building.

The installation of fire hydrants should be provided along highways at a distance of no more than 2.5 meters from the edge of the roadway, but not less than 5 meters from the walls of buildings; fire hydrants may be located on the roadway. In this case, the installation of fire hydrants on a branch from the water supply line is not allowed.

The placement of fire hydrants on the water supply network must ensure fire extinguishing of any building, structure, structure or part thereof served by this network from at least 2 hydrants with a water flow rate for external fire extinguishing of 15 or more liters per second, with a water flow rate of less than 15 liters per second - 1 hydrant.

REQUIREMENTS FOR SOURCES OF FIRE-FIGHTING WATER SUPPLY FOR A PRODUCTION FACILITY

Production facilities must be provided with external fire-fighting water supply. The placement of fire hydrants on the water supply network must ensure fire extinguishing of any building, structure, structure or part of a building, structure, structure served by this network.

The supply of water for fire extinguishing purposes in artificial reservoirs should be determined based on the estimated water consumption for external fire extinguishing and the duration of fire extinguishing.

Fire hydrant and fire pump

Purpose, device, operation, procedure for use and operation

A hydrant with a fire column is a water intake device installed on a water supply network and designed to draw water when extinguishing a fire.

A hydrant with a column can be used when extinguishing a fire:

• as an external fire hydrant in case of connecting a fire hose to supply water to the place of fire extinguishing,
• as a water feeder for a fire truck pump.

Fire pump

Fire column design

The column consists of housing 8, head 1, cast from aluminum alloy AL-6, and socket wrench 3. At the bottom of the column body there is a bronze ring 10 with threads for installation on a hydrant. The column head has two pipes with coupling connecting heads for connecting fire hoses.

The opening and closing of the pipe is carried out by valves, which consist of a cover 5, a spindle 6, a poppet valve 7, a handwheel 4 and a stuffing box seal.

The socket wrench is a tubular rod, in the lower part of which a square coupling 9 is fixed for rotating the hydrant rod. The socket wrench is rotated by handle 2 attached to its upper end. The sealing of the rod exit point in the column head is ensured by a stuffing gland.

Column hydrant

Column hydrant It is a hydrant combined with a water standpipe. Water is drawn from the hydrant using a pressure hose with a diameter of 66 mm with direct supply to the fire nozzle or fire truck pump.

The hydrant shutter is opened with a special key with a force of no more than 300 N, the spindle rotation speed is no more than 18 and at a water pressure in the network of no more than 1 MPa (10 kgf/cm2). The remaining water in the body of the hydrant after operation is removed by the ejector of the water dispenser by pressing its handle for 3...7 minutes.

Designed for collecting water from the water supply network to extinguish fires, as well as for domestic and drinking water supply.

Dispenser hydrant design

Depending on the design features and fire protection conditions of protected objects, hydrants are divided into:

Underground fire hydrant

Fire underground hydrant, shown in the figure, consists of three parts cast from gray cast iron: valve box 9, riser 5 and installation head 4.

Cast Iron Hollow Valve 12 drop-shaped, assembled from two parts, between which a rubber o-ring 11 is installed. There are clamps in the upper part of the valve 8, which move in the longitudinal grooves of the valve box.

Spindle 7, passed through the hole in the riser crosspiece, is screwed into a threaded bushing in the upper part of the valve. A coupling is attached to the other end of the spindle 6, into which the square end of the rod 3 enters. The upper end of the rod also ends with a square for the socket wrench of the fire column.

By rotating the rod and spindle (using a fire pump socket wrench), the hydrant valve, thanks to the presence of clamps, can only make translational movement, ensuring its opening or closing.

When opening and lowering the valve, one of its clamps closes the bleed hole 2, located at the bottom of the valve box, preventing water from entering the hydrant well. To stop the withdrawal of water from the water supply network, by rotating the rod and spindle, the hydrant valve rises upward, ensuring that the drain hole is opened by the latch. The remaining water in the riser after operation of the hydrant flows through the drain hole and drain pipe 1 into the hydrant well, from where it is removed by force. To prevent water from entering V The hydrant body has a check valve installed on the drain pipe.

Above ground fire hydrant

Above ground fire hydrant, is presented schematically in the figure.

Although there is an opinion among many that the use of ground hydrants is impossible in countries with cold climates (such as Russia, Ukraine, Belarus, etc.), the example of a city like Chicago can be cited to immediately counterbalance this opinion. In short, the use of above-ground GHGs is possible in any climatic conditions; it is only necessary to choose the appropriate type of above-ground GHGs, namely with a constant supply of water (wet GHG) or with a regulated supply of water (dry GHG).

The last option is, in principle, a Moscow-style steam generator with a fire column screwed onto it. The use of above-ground GHGs not only removes all the disadvantages of above-ground GHGs, but also reduces the time for free development of a fire, and from an aesthetic point of view, they can be much more attractive than it might seem at first glance.

Operation of fire hydrants and pumps

Fire hydrants, as a rule, are installed along the street on the water supply network at a distance of 50...120 m from each other, while ensuring convenient access and use. To locate underground hydrants on the walls of buildings and structures against which the hydrant is installed, attach a special sign or light indicator of the location of the hydrant.

The water extraction by the fire truck pump must be carried out through two hoses (66 mm in diameter) connected parallel to the column, one of which must be a pressure-suction hose, and the other a pressure hose.

The hydrant valve is opened in the following order:

• turn the column socket wrench handle 2…3 turns and fill it with water,
• after the noise stops, you should pause and continue rotating the socket wrench handle until the hydrant valve is completely open,
• then rotate the handwheels counterclockwise, open the valves of the pressure pipes of the column,
• close the hydrant in the reverse order, with the valves of the dispenser pressure pipes closed,
• When unscrewing the column, the socket wrench must not move.

Requirements of labor safety rules when working with fire pumps and hydrants

When using a fire hydrant, its cover is opened with a fire hook or crowbar. In this case, it is necessary to ensure that the lid does not fall on the feet of the person opening it.

If the air temperature is negative (not lower than -15° C), then the hydrants are inspected only externally, and at lower temperatures it is forbidden to open the well covers. Hydrants with water supply are checked only using a fire pump, since the use of socket wrenches or other devices can lead to an accident.

Literature:

• Federal Law of July 22, 2008 N 123-FZ Technical regulations on fire safety requirements;
• Order No. 1100n “On approval of the Rules for labor protection in units of the federal fire service of the State Fire Service” dated December 23, 2014;
• Dmitriev V.D. History of the development of water supply and sanitation in St. Petersburg. St. Petersburg, 2002;
• Fire water supply: Textbook. - M.: Academy of the State Fire Service of the Ministry of Emergency Situations of Russia, 2008;
• Textbook V.V.Terebnev, V.A.Grachev, A.V.Podgrushny, A.V.Terebnev Fire drill training.

3. FIRE-FIGHTING WATER SUPPLY TO SETTLEMENTS AND INDUSTRIAL FACILITIES

3.1 Classifications of water supply systems

Water supply system- a complex of interconnected devices and structures that provide consumers with water in the required quantity and specified quality. The water supply system includes devices and structures for collecting water from a water supply source and transporting it; processing, storage, regulation of supply and distribution between consumers.

Water supply scheme- sequential arrangement of these structures from source to consumer, their relative location relative to each other.

Water supply systems must be designed in accordance with the requirements for the design of external networks and water supply structures, as well as other regulatory and technical recommendations and requirements for water by consumers. In this case, it is necessary to take into account local conditions, the diversity of which leads to the fact that the water supply system of any facility is unique and inimitable in its own way.

The whole variety of water supply systems encountered in practice is classified according to the following main characteristics:

- by purpose: household and drinking; fire protection; production; agricultural. The listed types of systems can be either independent or combined. Systems are combined if the requirements for water quality are the same or it is economically beneficial;

- by the nature of the natural sources used: systems receiving water from surface sources (rivers, lakes, reservoirs, seas, oceans); systems that take water from underground sources (artesian, groundwater); mixed supply systems (using different types of water sources);

- on a territorial basis(coverage): local (one object) or local; group or district, serving a group of objects; off-site; on-site;

- by water supply methods: gravity (gravity); pressure (with mechanical water supply using pumps); combined;

- according to the frequency of use of consumed water(for enterprises): direct-flow (single use); with consistent use of water (two or three times); circulating (repeated use of water, carried out in a closed, semi-closed circuit or with the discharge of part of the water - blowing); combined;

- by types of objects served: urban; village; industrial; agricultural; railway, etc.;

- according to the method of delivery and distribution of water: centralized; decentralized; combined.

Water supply systems in populated areas are usually centralized. Moreover, depending on local conditions and economic feasibility, they can be separate - with their own sources of water supply for each of the zones (residential or industrial) - or combined - with a common source of water supply for both zones (Fig. 3.1).

Figure 3.1 – Water supply systems: A - centralized separate; b - centralized united; V - combined: 1 - water intake structure; 2 - pumping station NS-1; 3 - treatment facilities; 4 - clean water tanks; 5 - NS-N; 6 - water tower; 7 - water conduits; 8 - distribution water supply network; 9 - populated area; 10 - production zone.

Decentralized (local) water supply systems are built for individual remote local consumers or groups of buildings, as well as settlements planned for resettlement.

Based on reliability or the degree of security of water supply, centralized water supply systems are divided into three categories (Table 3.1).

Water supply systems (water pipelines) used simultaneously for domestic drinking and (or) industrial water supply and for extinguishing fires, or special fire-fighting water supply can be of low or high pressure (Fig. 3.2):

a) with water supplied from the water supply network through low-pressure hydrants (if there is a fire station, the necessary pressure is provided using fire trucks or motor pumps);

b) in the absence of a fire station, the pressure is created by stationary fire pumps installed in pumping stations, and the network pipes must be selected taking into account the increase in pressure during a fire.

Figure 3.2 – Schemes for extinguishing a fire from a water supply system: A - low pressure; b - high pressure

A special fire-fighting water supply can be installed with water supplied directly from fire-fighting tanks or natural reservoirs (rivers, lakes, ponds); the required pressure is provided by fire fighting vehicles or motor pumps.

In settlements with a population of more than 5 thousand people, the fire water supply must be low pressure. Fire-fighting water supply to settlements with a population of up to 5 thousand people is also allowed from natural or artificial reservoirs or reservoirs with water taken from them by fire truck pumps or motor pumps. In this case, the required number of reservoirs or reservoirs is determined based on the fact that their radius of action should not exceed when extinguishing a fire: with auto pumps - 200 m, with motor pumps - 100-150 m. The volume of each reservoir must be designed for the water flow required to extinguish the fire within 3 hours. Fire-fighting tanks are replenished from the drinking water supply. The choice of a fire-fighting water supply system is justified by technical and economic calculations. For settlements with a population of up to 50 people, when built with one or two-story buildings, as well as for detached industrial buildings of fire resistance class I and II with a volume of up to 1000 m 3, fire-fighting water supply may not be provided.

An approximate water supply scheme for a settlement is shown in Fig. 3.3.

Figure 3.3 – Scheme of water supply to a settlement using a surface water source: 1 - source of water supply; 2 - water intake structure; 3 - pumping station of the 1st lift; 4 - water treatment plant; 5 - clean water tank (RCW); 6 - pumping station of the second lift; 7 - pressure control structure (water tower); 8 - distribution network of a populated area; 9 - gravity water conduits; 10 - pressure water conduits, 11 - suction water conduits, 12 - pressure of pumps of the first rise, 13 - pressure of pumps of the first rise, 14 - line of free pressures in the distribution network.

3.2 Water pipes for external fire extinguishing

Water supply schemes are carried out depending on the nature of the water supply system, which must serve firefighting needs, and its purpose.

According to the method of creating pressure, fire-fighting water pipelines are:

1) high pressure, which are divided into:

a) constant high pressure water supply systems;

b) high pressure, increased only during a fire. In this case, the pressure in the water supply network is sufficient to directly supply water to extinguish fires from hydrants installed on the network (without the help of imported pumps);

2) low pressure(supply of water for extinguishing from imported pumps).

Constant high pressure fire water supply system are rarely arranged due to the large material costs of creating a water supply network serving only fire needs, and the need to install a high water tower or a separate pneumatic installation.

Fire-fighting high-pressure water supply, increased only during a fire, are installed mainly at stationery mills, large oil refineries and other industrial facilities characterized by a high fire hazard,

The high-pressure fire-fighting water supply system, which is increased during a fire, is combined with the drinking water supply system of industrial enterprises. The pressure for fire extinguishing increases only in the drinking water network; in the industrial water supply, the pressure at this time remains unchanged, so in the event of a fire, production processes that require constant pressure in the network are not disrupted. The construction of fire-fighting water pipelines combined with utility and drinking water supply systems is also advisable because the utility network, as a rule, is more extensive than the production network and covers the largest part of the facility territory. With such water supply systems, external fire extinguishing can be carried out directly from hydrants without imported pumps, and internal fire water supply is ensured by installing fire risers with fire hydrants in the building. In this case, the water tower is built with a height sufficient for gravity supply of water to extinguish the fire from internal fire hydrants (in the initial stage of the fire). During a fire, the water tower tank is turned off using an automatic device after starting the fire pump, since the pressure developed by the fire pump exceeds the height of the water tank.

A high-pressure fire-fighting water supply system, combined with a production water supply system, is installed in rare cases when in the event of a fire it is necessary to supply under high pressure the entire amount of water required for production needs (as a rule, this amount is significant).

Low pressure fire water supply, combined with a household and drinking water supply system, is calculated in such a way that during a fire only the amount of water supplied increases, while the pressure in the network is maintained at least 10 m. With low-pressure water supply systems, it is not necessary to turn off the water tower or counter-tank during a fire. Such water pipelines are widespread in cities and towns, where there are no other networks except household ones. Water for extinguishing fires is withdrawn from such water pipelines using imported fire pumps (auto pumps, motor pumps, etc.).

A low-pressure fire-fighting water supply system, combined with an industrial water supply system, is installed in industries where the fire flow rate, compared to the production water supply, is small and does not affect the pressure of the industrial water supply system. However, if for firefighting needs it is necessary to start an additional pump, the pressure in the network may decrease, which is not always allowed by technology requirements. With the water supply system under consideration, water is taken for external fire extinguishing from the network of a combined low-pressure industrial and fire-fighting water supply system, and internal fire extinguishing is from internal utility and industrial water supply systems. This scheme is rational, because the internal network in this case supplies water both for domestic and drinking needs and for the needs of internal fire extinguishing.

Fire-fighting water supply systems are sometimes combined simultaneously with drinking and industrial water supply systems. In this case, the water supply network is unified, and the water supply lines can be of high and low pressure.

The given fire-fighting water supply diagrams are used in various combinations. The choice of one or another scheme depends on the nature of the production, the territory it occupies, the characteristics of the fire hazard of the production, the flow rate of water supply sources and technical and economic indicators, as well as the local conditions of the object in question.

With high production water consumption, in some cases the scheme of a high-pressure fire-fighting water supply system combined with a household and drinking water supply system turns out to be more rational.

If a low-pressure fire water supply is acceptable for a facility, then it can be combined with a production one, provided there is sufficient coverage of the buildings and structures on the premises by the water supply network.

The choice of water supply system is influenced by the characteristics of the internal fire water supply system, sprinkler and deluge equipment, as well as stationary fire extinguishing installations. In addition, when choosing a fire water supply, it is necessary to consider whether there is a fire brigade on or near the site.

Low pressure water pipelines can be constructed only if there are fire brigades with mobile fire pumps at the site or in its immediate vicinity. It is advisable to install high-pressure water pipelines in the absence of a fire brigade or in the absence of mobile fire pumps to supply the full calculated amount of water to extinguish a fire (for example, at objects remote from populated areas). When choosing a water supply scheme, it is necessary to take into account the technical and economic indicators of the technical solution option, including capital investments and operating costs of the water supply system.

Table 3.2 shows the characteristics of fire-fighting water supply systems, reflecting the advantages and disadvantages of options when choosing a rational scheme.

Table 3.2 - Advantages and disadvantages of fire-fighting water supply scheme options

continuation of table 3.2

3.3 Internal fire water supply

The internal water supply must provide the water supply to generate the jets necessary to extinguish the fire. This requires the construction of a water tower with a certain supply of water, continuous operation of pumps, or a pneumatic water supply device that replaces the water tower.

The influence of the requirements of internal fire water supply on the choice of external water supply scheme can be shown with an example. Let's assume that the fire-fighting water supply system can be constructed according to a low-pressure scheme and combined with a production water supply system supplying untreated water (not suitable for domestic and drinking needs). The question arises: to which water supply system can the internal fire-fighting network be connected?

In the case of combining the internal fire-fighting network with the industrial one, it is necessary to take into account the effect of an increase in pressure in the network on the operation of the external industrial water supply, based on the conditions for extinguishing fire from internal fire hydrants. If the required pressure for the industrial water supply is small, and the flow rate is high and the pressure for extinguishing through the internal taps is greater than the production pressure, then it is not practical to combine the internal fire-fighting water supply with the industrial one.

3.4 Sprinkler and deluge equipment

Sprinkler equipment designed to automatically signal a fire and extinguish it. The equipment consists of pipes laid indoors under the ceiling. Sprinklers are installed on the pipes, which automatically open when the temperature in the room rises to a predetermined limit and supply water to the fire in the form of drip water jets. The sprinkler system is constantly under water pressure to ensure its supply to the fire when the sprinkler lock is opened. The water source for sprinkler equipment is household fire-fighting, industrial fire-fighting and other water pipelines, as well as natural water sources and artificial reservoirs.

Depending on the type of water source, the type of water feeder is selected. Typically, sprinkler equipment has two water feeders: auxiliary (automatic) and main. An automatic water feeder (water tank, hydropneumatic installation, water supply system) supplies water and the installation until the main water feeder is switched on. Pumping and power equipment, water pipelines and spare tanks are used as the main water supply. In standby mode, the pipelines of sprinkler equipment are filled with water or air, depending on the air temperature in the room. Distribution networks of sprinkler equipment are divided into independent sections (usually a section protects a room or floor of a building) with dead-end or ring piping. Droplet water jets are formed when water exits the sprinkler at a pressure of at least 5 m.

Deluge equipment designed for automatic or manual fire extinguishing in premises by irrigation with drip water jets over the estimated area of ​​the building. Deluge equipment is also used to create water curtains in the openings of doors or windows, to irrigate individual elements of technological equipment, etc. Such equipment is used for fire-hazardous objects where rapid spread of fire is possible. When flammable substances and liquids burn, deluge equipment localizes the fire (restrains the development of the fire), allows firefighters to approach the fire and prevents the fire from spreading to neighboring objects. The design of deluge equipment is similar to sprinkler equipment, only instead of sprinklers, deluges are installed on the distribution network (sprinklers without a low-fusible lock) and the water supply is automatically turned on at the command of a fire detector responding to one of the factors accompanying the fire (heat, smoke, flame).

Stationary local installations used to extinguish fires in certain areas of technological installations of particularly high fire danger, when the use of sprinkler and deluge equipment is ineffective. The extinguishing effect in this case is achieved by instantly supplying a large amount of water to the fire in a short period of time. In this case, extinguishing the flames of solid combustible materials and liquids is achieved by supplying sprayed or mist-like water jets. To form such jets, special sprinklers are used, into which water is supplied under high pressure (up to 1 MPa).

Water-foam fire extinguishing installations used to extinguish flames of flammable and combustible liquids. These installations are most widespread in fire protection systems in the chemical, petrochemical and other industries where oil and natural gas are produced and processed. The fire extinguishing agent in such installations is foam, which is obtained from a 4-6% aqueous solution of foaming agents. Foam installations have a sprinkler or deluge design. Their design is similar to stationary water fire extinguishing installations. The difference is that sprinklers are replaced by foam sprinklers, and deluges are replaced by foam generators. In addition, water feeders of foam installations are additionally equipped with dispensers for introducing the required amount of foaming agent into the water flow.

3.5 Monitor installations

Fire monitors are used to supply and control high-power water or foam jets. For this purpose, high-capacity fire monitors (up to 100 l/s) are installed on special towers, roofs of buildings or platforms and connected to a special high-pressure fire-fighting water supply system.

Fire monitors are designed to extinguish fires in timber and lumber warehouses, on high-altitude technological equipment (for example, distillation and vacuum columns of oil refineries), as well as warehouses with liquefied flammable gas. For the operational operation of the monitor, high-speed valves are provided for turning on and off the liquid supply from the water supply system.

Fire monitors are available with manual and automated drives. The above diagrams determine only the composition and relative position of the elements of the water supply system. The dimensions of individual structures and installations, the number and power of pumps, the capacity of tanks, the height and capacity of water towers, and the diameters of pipes are calculated depending on the flow rate of the supplied water and the forecasted operating mode for them.

The main factor that determines the operating parameters of the elements of the water supply system is the mode of water consumption by the consumers whom this system serves. Unlike many engineering systems, which are calculated based on predetermined and predetermined loads, water supply systems must take into account the continuously changing water supply regime, therefore, when designing water supply systems, accurate forecasting of water consumption is necessary.

For industrial enterprises, water consumption for production needs is set in accordance with the technological regulations for water consumption. It is more difficult to predict water consumption in populated areas, since water consumption by the population is determined by a number of factors related to people’s lifestyle and work activities.

Fire water supply

Fire-fighting water supply is a set of measures to provide water to various consumers to extinguish a fire. The problem of fire-fighting water supply is one of the main ones in the field of firefighting. Modern water supply systems are complex engineering structures and devices that provide reliable water supply to consumers. With the development of water supply to populated areas and industrial enterprises, their fire protection is improving, since the design, construction, and reconstruction of water pipelines take into account not only economic and industrial needs, but also fire safety needs. Basic fire safety requirements require the supply of standard volumes of water under a certain pressure during the estimated fire extinguishing time.

Types of water pipelines. Classification of water supply systems by pressure.

According to their purpose, water supply systems are divided into utility and drinking water supply, industrial and fire safety. Depending on the pressure, fire-fighting water pipelines of high and low pressure are distinguished. In the high-pressure fire-fighting water supply system, within 5 minutes after the fire is reported, the pressure necessary to extinguish the fire in the tallest building without the use of fire engines is created. For this purpose, stationary fire pumps are installed in pumping station buildings or in other separate rooms.

In low-pressure water supply systems during a fire, fire pumps are used to create the required pressure, which are connected to fire hydrants using suction hoses.

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.

All water supply structures are designed so that during operation they pass the calculated water flow for fire needs with the maximum water flow for household, drinking and industrial needs. In addition, an untouchable supply of water is provided in clean water reservoirs and water towers for extinguishing fires, and fire pumps are installed in second-lift pumping stations.

Pump-hose systems, which are assembled when extinguishing fires, are also elementary high-pressure fire-fighting water supply systems, consisting of a water supply source, a water intake (suction grid), a suction line, a combined pumping station of the first and second lift (fire pump) , water pipelines (main hose lines), water supply network (working hose lines).

Water towers are designed to regulate pressure and flow in the water supply network. They are installed at the beginning, middle and end of the water supply network. A water tower consists of a support (trunk), a tank and a tent-device that protects the tank from cooling and freezing the water in it. The height of the tower is determined by hydraulic calculation taking into account the terrain. Typically the tower height is 15...40 m.

The capacity of the tank depends on the size of the water supply system, its purpose and can vary widely: from several cubic meters on low-power water supply lines to tens of thousands of cubic meters on large urban and industrial water supply lines. The size of the control tank is determined depending on the water consumption schedules and the operation of pumping stations. In addition, an emergency fire reserve is included to extinguish one external and one internal fire within 10 minutes. The tank is equipped with discharge, collapsible, overflow and mud pipes. Often the discharge and discharge pipes are combined.

A type of water towers are water tanks, which are designed not only to regulate pressure and flow in the water supply network, but also to store a fire-fighting supply of water for extinguishing fires for 3 hours. Reservoirs are located in elevated places.

Water tanks and towers are connected to the water supply network in series and in parallel. When switched on in series, all the water from the pumping stations passes through them. In this case, the discharge and collapsible pipes are not combined, and they work separately. At minimum water consumption, excess water is accumulated in a reservoir or tank, and at maximum, this supply is sent to the water supply network.

When connected in parallel to the water supply network, excess water is supplied to reservoirs and tanks (at minimum water consumption), and at maximum water consumption it is sent to the network. In this case, the injection and distribution pipelines can be combined. Measuring devices are provided to monitor the water level in tanks and reservoirs.

Based on the type of facility being serviced, water supply systems are divided into urban, settlement, as well as industrial, agricultural, railway, etc.

Based on the type of natural sources used, a distinction is made between 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 supplying water, there are pressure pipelines with mechanical water supply by pumps and gravity (gravity) ones, which are installed in mountainous areas when the water source is located at an altitude that ensures a natural supply of water to consumers.

According to their purpose, water supply systems are divided into household and drinking water systems that satisfy the needs of the population; production technological processes supplying water; fire and combined. The latter are usually held in populated areas. From these same water pipelines, water is also supplied to industrial enterprises if they consume a small amount of water or the conditions of the production process require drinking-quality water.

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 fire water supply with household water supply, and not with industrial water supply, is explained by the fact that the industrial water supply network is usually less extensive and does not cover all volumes of the enterprise. In addition, for some technological production processes, water must be supplied under a strictly defined pressure, which will change when extinguishing a fire. And this can lead either to an increase in water consumption, which is not economically feasible, or to a breakdown of production equipment. An independent fire-prevention water supply system is usually installed at the most fire-hazardous facilities—enterprises of the petrochemical and oil refining industries, oil and petroleum product warehouses, lumber yards, liquefied gas storage facilities, etc.

Water supply systems can serve one object, for example a city or an industrial enterprise, or several objects. In the latter case, these systems are called group systems. If a water supply system serves one building or a small group of closely spaced buildings from a nearby source, it is called a local system. To supply water under the required pressure to different areas of the territory of a populated area, which have a significant difference in elevations, zone water supply is arranged. A water supply system that serves several large water consumers located in a certain area is called a district one.

On the territory of most settlements (cities, towns) there are different categories of water consumers who have different requirements for the quality and quantity of water consumed. In modern city water supply systems, water consumption for technological needs of industry averages about 40% of the total volume supplied to the water supply network. Moreover, about 84% of water is taken from surface sources and 16% from underground

The water supply or design system is usually divided into two parts: external and internal. External water supply includes all structures for the intake, purification and distribution of water through a water supply network up to the entrances to buildings. Internal water pipelines are a set of devices that ensure the receipt of water from the external network and its supply to water distribution devices located in the building.

The supply of water for firefighting purposes in cities is provided by fire trucks from hydrants installed on the water supply network. In small cities, additional pumps are turned on in the PS-I to supply water for extinguishing fires, and in large cities, fire flow constitutes an insignificant part of water consumption, therefore they have practically no effect on the operating mode of the water supply system.

In accordance with modern standards, in settlements with a population of up to 500 people, which are located mainly in rural areas, an integrated high-pressure water supply system must be installed to provide household, drinking, industrial and fire-fighting needs. However, there are often cases when only a drinking water supply system is built, and for firefighting needs water is supplied by mobile pumps from reservoirs and reservoirs replenished from the water supply system.

In small settlements, for economic and fire-fighting needs, local water supply systems are most often installed with water taken from underground sources (mine wells or boreholes). Centrifugal and piston pumps, Airlift systems, wind power plants, etc. are used as water-lifting devices. Centrifugal pumps are the most reliable and easy to use. As for other water-lifting devices, due to their low productivity they can only be used to replenish fire water supplies in reservoirs, reservoirs, and water towers.

Water supply sources

In accordance with the two categories of natural water sources, water receiving 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, sanitary and hygienic requirements for water quality, and technical and economic considerations. If 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 facility supplied with water (to reduce the cost of water supply and water supply).
Groundwater occurs at different depths and in different rocks.

For water supply use:

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

non-pressure groundwater with a free surface, contained in layers that do not have a water-permeable roof;

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

mine and mine waters (usually for industrial water supply), i.e. groundwater entering drainage structures during the extraction of minerals.

Construction of a fire hydrant and requirements for operation in winter and summer

A hydrant with a fire column is a water intake device installed on a water supply network and designed to draw water when extinguishing a fire.

When extinguishing a fire, a hydrant with a column can be used, firstly, as an external fire hydrant in the case of connecting a fire hose to supply water to the fire extinguishing site and, secondly, as a water supply for a fire truck pump.

Depending on the design features and fire protection conditions of protected objects, hydrants are divided into underground and above-ground.

Underground hydrants are installed in special wells covered with a lid. The fire hose is screwed onto the underground hydrant only when it is in use. An above-ground hydrant is located above the surface of the ground with a column attached to it.

A fire hydrant is designed to draw water from the water supply network to extinguish fires; it consists of a riser, a valve, a valve box, a rod, a threaded installation head and a cover. If the groundwater level is high, a check valve is installed at the drain hole of the valve box.

Conditional bore, mm................................................... .................................... 125

Rotational speed of the rod until the valve is fully opened, revolutions......

Force when opening a hydrant, N (kg)................................................. ..............

A hydrant column is installed on a water supply network using a fire stand without installing a well. The throughput capacity of the combined hydrant is 20 l/s.

The fire stand is used for opening and closing a fire hydrant, as well as connecting fire hoses when drawing water from the water supply network to extinguish fires. The main parts of the speaker are the body and the head. At the bottom of the housing there is a threaded ring for connecting the column to a fire hydrant. In the upper part there are column controls and two pipes with connecting heads and two valves. A central key (tubular rod) with a square coupling at the bottom and a handle at the top passes through the gland in the head of the column. The handle is rotated with the valves of the pressure pipes closed. When the valves are open, the handwheels will fall into the field of rotation of the handle. Thus, the column has a lock that prevents the central key from turning when the valves of the pressure pipes are open. Remove the column from the hydrant only when the hydrant valve is closed.

Technical characteristics of underground fire hydrant

Conditional bore, mm................................................... ......................................

Working pressure, MPa (kgf/cm2) .............................................. ........................

Conditional bore of the connecting head, mm....................................................

Weight, kg, no more................................................... ...........................................

Requirements for the operation of fire hydrants in winter and summer

There are mandatory rules for the operation of fire hydrants. Failure to properly handle fire hydrants can lead to breakdowns in the water supply network, interruption of water supply, and accidents.

Preparation of fire-fighting water supply for operation in winter conditions is carried out:

 urban water supply - during the autumn inspection by mobile teams of AVR REWS (departments);

 object water supply - during the autumn inspection by the water supply services of the objects.

Preparation of fire-fighting water supply for operation in winter conditions includes:

 pumping water from the risers of Moscow-type fire hydrants and sealing drain holes with wooden plugs;

 at established sub-zero outside air temperatures, pumping water from hydrant wells filled above the riser level and then performing step 1;

 fire hydrants subject to flooding by groundwater and melt water are taken into special accounting (Appendix No. 1 “Instructions...”) by linear sections of REWS and district fire departments with a mandatory mark in the book of fire-fighting water supply inspections, subsequent monitoring of their condition by REWS, pumping water from risers after thaws (if necessary) and mandatory transfer of information to regional fire departments;

 filling hydrant wells with special heat-insulating filler.

Requirements for the commissioning of new sources of fire-fighting water supply.

To the fire hydrants

Fire hydrants should be installed on ring water supply networks. It is allowed to install fire hydrants on dead-end lines, regardless of the water consumption for fire extinguishing, provided that their length does not exceed 200 meters.

The diameter of the water supply pipes on which fire hydrants are installed is determined by calculation in accordance with clause 8.46 of SNiP 2.04.02-84 "Water supply. External networks and structures", but the minimum diameter of water supply pipes in populated areas and industrial enterprises must be no less 100 mm, in rural areas - at least 75 mm, the maximum diameter of pipes should not exceed 500 mm.

Fire hydrants should be located along highways at a distance of no more than 2.5 m from the edge of the roadway, but no closer than 5 m from the walls of buildings. It is allowed to place hydrants on the roadway. In the historical part of the city, it is allowed to place fire hydrants in accordance with the requirements of clause 8.55 of VSN-89. The distance between hydrants should not exceed 150 meters.

Around the hatches of wells located in built-up areas, off-road pavements or in a green zone, blind areas 1 m wide should be provided with a slope from the hatches; the blind areas should be 0.05 m higher than the adjacent territory; on the roadway of streets with improved permanent surfaces, manhole covers must be flush with the surface of the roadway; well hatches on water pipelines laid in undeveloped areas should be 0.2 m above the ground surface.

There must be a free access to the hydrant with a width of at least 3.5 meters.

At the location of the fire hydrant, an indication sign must be installed at a height of 2-2.5 m from the ground surface (signs at facilities made in accordance with GOST 12.4.026-76 “Signal colors and safety signs” are installed directly at water sources and in the direction of movement towards him). The plate must be 12x16 cm in size, red and have white inscriptions indicating:

 hydrant type (Moscow type hydrant is designated by the letter M);

 diameter of the water supply network in millimeters (inches);

 the nature of the water supply network (a dead-end network is indicated by the letter T in the upper left corner of the sign);

 fire hydrant number (must match the number of the house on which the coordination plate is located). Recording numbers with the number “0” in front (01.02.03., etc.) means that the indicator signs for these fire hydrants are located on trees, metal poles or street lighting poles, without reference to house numbers;

 digital value of the distance in meters from the sign to the hydrant.

In accordance with clause 1.12. GOST 12.4.009-83 fire hydrant signs must be illuminated with lamps or made using fluorescent or reflective coatings

Hydrants in wells are installed vertically. The axis of the installed hydrant should be located no closer than 175 mm and no further than 200 mm horizontally from the wall of the manhole neck. The distance from the top of the hydrant to the top edge of the hatch should be no more than 400 mm and no less than 150 mm. The technical condition of the fire hydrant is checked by installing a column with the obligatory release of water, and there should be no leakage of water in the flange connections of the hydrant.

After fire hydrants are put into operation, an act is drawn up in 4 copies (one copy each for the fire department, DSPT, REVS (department) and the organization that carried out the construction and installation work).

When accepting hydrants located on on-site water supply networks into operation, it is necessary to additionally test the network for water loss. After fire hydrants are put into operation at the site, a free-form act is drawn up in 4 copies (one for the district fire department, the second for the customer, the third for the general contractor, the fourth for DSPT). Based on the act, the characteristics of the fire water supply of the facility are included in the summary statement of the facility water supply.

To gravity wells

To extract water from natural water sources with swampy banks or the impossibility of direct water intake from them for fire extinguishing purposes, gravity (receiving) wells are installed.

Gravity wells must have plan dimensions of at least 0.8 x 0.8 m. They can be made of concrete, stone and wood. The well must be equipped with two covers, the space between which is filled with insulating material in the winter, which protects the water from freezing.

The depth of water in the well must be at least 1.5 m. The well is connected to the water source by a supply pipe, the diameter of which must be at least 200 mm. The end of the pipe extending into the water source must be located at least 0.5 m above the bottom and at least 1.0 m below the low water horizon. A metal wire mesh must be attached to the end of the pipe on the water source side to prevent suction into the water source. pipe of fish and various items.

There must be free access to the gravity well, designed for the simultaneous installation of two fire trucks. A light or fluorescent sign with the inscription “SKN” must be installed at the location of the gravity well.

To fire ponds

The need to install and the required volume of fire-fighting reservoirs for objects and settlements specified in note 1 of clause 2.11. should be determined by water consumption standards for the estimated fire extinguishing time in accordance with the instructions of paragraphs 2.13.-2.17. and 2.24. SNiP 2.04.02-84.

The number of fire reservoirs must be at least two, and in each reservoir half the volume of water for fire extinguishing must be stored (clause 9.29. SNiP 2.04.02-84).

Fire reservoirs should be placed based on the condition that they serve buildings located within the radius of:

If there are car pumps - 200 m;

If there are motor pumps - 100-150 m, depending on the type of motor pumps (clause 9.30. SNiP 2.04.02-84).

The distance from reservoirs to buildings of 3, 4 and 5 degrees of fire resistance and to open warehouses of combustible materials must be at least 30 m, to buildings of 1 and 2 degrees of fire resistance - at least 10 m (clause 9.30. SNiP 2.04.02-84).

If the direct intake of water from a fire reservoir using motor pumps or motor pumps is difficult, receiving wells with a volume of 3-5 cubic meters should be provided. meters. The diameter of the connecting pipeline should be taken from the condition of passing the calculated water flow for external fire extinguishing, but not less than 200 mm. In front of the receiving well, a well with a valve should be installed on the connecting pipeline, the steering wheel of which should be located under the manhole cover. A grill should be provided on the connecting pipeline on the reservoir side.
Water must be drawn from each reservoir by at least two fire pumps, preferably from different sides.

Driveways with turning areas for fire trucks, no less than 12x12 m in size, are arranged to fire reservoirs and suction wells.

At the location of the fire reservoir, a light or fluorescent sign must be installed with the following written on it: the letter index PV, digital values ​​of the water reserve per cubic meter. meters and the number of fire trucks that can be simultaneously installed on the site near the reservoir.

To ensure reliable water intake from natural reservoirs with high bank slopes, as well as significant seasonal fluctuations in water horizons, access points (piers) are built that can withstand the load of fire trucks. The access area (pier) should be located no higher than 5 m from the low water horizon (LWH) and no less than 0.7 m above the high water horizon (HWH) and be equipped with a drainage tray for suction hoses. The depth of water, taking into account freezing in winter, must be at least 1 m, otherwise, a pit (pit) is built at the intake site. The width of the platform flooring must be at least 4.5-5 m with a slope towards the shore and have a strong side fence 0.7-0.8 m high. At a distance of 1.5 m from the longitudinal edge of the platform, a thrust beam with a cross-section of less than 25x25 cm.

Chiefs (deputy chiefs) of units must go to technical acceptance of new or reconstructed sources of fire-fighting water supply.

Note: Acceptance of fire hydrants after completion of work on the construction of new and reconstruction of existing fire water supply networks is carried out by SPT TsUS UGPS (2nd shift), or in agreement with it.

Fire water supply inspections

Fire water supply inspections are carried out:

On city water supply networks twice a year (spring - from April 1 to June 1; autumn - from July 15 to November 1) by the forces of mobile teams of emergency restoration work (AVR) of water supply network operating areas (REVS) and branches of the State Enterprise "Vodokanal S" .-Petersburg" with the obligatory presence of a representative of the HR. To carry out an inspection by the linear section of the REWS (department) of the State Enterprise "Vodokanal of St. Petersburg", a "Schedule for the inspection of fire hydrants for the REWS (department)" is drawn up (Appendix No. 14 "Instructions..."), which is approved by the head of the REWS (department) and agreed upon head (deputy head) of the HR. During the spring inspection, only Leningrad type fire hydrants are checked; during the autumn inspection, all fire hydrants are checked.

Object fire-fighting water supply twice a year (spring - from April 1 to June 1; autumn - from August 15 to November 1) by the duty guards of fire departments with the mandatory presence of a representative of the facility's water supply service. The departments, led by the chief of guard, go to check the facility’s water supply from 9:30 a.m. to 11:00 a.m. and after 5:00 p.m., in agreement with the senior engineer of the Department of State Border Guard Service.

When conducting fire-fighting water supply inspections (city and facility), the following is checked:

 presence of signs of fire hydrants, reservoirs, gravity wells, piers, entrances and correspondence of coordinates using a tape measure;

 presence and condition of entrances to water sources;

 presence and condition of the outer cover of hydrants and gravity wells. In winter, the lid must be cleared of ice, the presence of loose snow on it no more than 10 cm is allowed. Responsibility for removing ice and snow from the lids of fire hydrants and gravity wells rests with the heads of REWS (departments) of the State Enterprise "Vodokanal of St. Petersburg" and economic objects (organizations, institutions);

 internal condition of the fire hydrant well, gravity well;

 availability of water and pressure by installing a column on all hydrants with the obligatory release of water. During the spring inspection of Leningrad-type city hydrants, mud-filled wells are cleaned (if necessary), and during the autumn inspection of all city and facility hydrants;

 measures are being taken to prepare them for operation in winter;

 depth of the reservoir in the place intended for lowering the fence mesh. In winter, when conducting fire-tactical exercises and exercises, pay attention to the presence and size of the ice hole, clearing the site for the installation of fire trucks;

 the condition of supporting structures and decking, the presence of side railings, abutment beam and outlet tray at the fire pier;

 checking gravity wells and reservoirs by installing motor pumps with water intake and release.

Note: during inspections, it is not allowed to use socket wrenches, poles and pieces of pipe to open hydrants and start water without installing dispensers (with the exception of German-style hydrants).

Fire water supply checks on city networks.

During the period of fire-fighting water supply inspections on city networks, the mobile brigade of the AVR REVS (department) of the State Enterprise "Vodokanal of St. Petersburg" arrives in its transport according to the schedule at the fire center, from where it proceeds to the inspection site with a representative of the fire department (senior firefighter). The results of the inspection are recorded by the senior firefighter in the fire water supply inspection book. If the water source is in good working order, then the date of inspection and signature is entered in the corresponding column; if the water source is not working properly, the nature of the malfunction is indicated according to the classification of defects (Appendix No. 8 “Instructions...”). The chiefs of guards on their duty days are personally responsible for ensuring that a representative of the fire department (senior firefighter) as part of the mobile brigade of the AVR REVS (department) of the State Enterprise "Vodokanal St. Petersburg" leaves to check the water supply according to the schedule.

Based on the results of the autumn and spring inspection of fire hydrants on the city network, an act is drawn up (Appendix No. 15 “Instructions ...”), which is approved by the head of the REVS (department) of the State Enterprise "Vodokanal St. Petersburg" and agreed upon by the head (deputy head) of the fire department. The act is drawn up in three copies: one - in the REVS (branch); the second - in the frequency converter; the third - in DSPT UGPS.

Information about the malfunction of hydrants on city networks in the area of ​​departure of the control unit after the end of the inspection is transferred to the deputy head of the hazardous production facility for service (senior engineer) for drawing up a GPN Order addressed to the head of the corresponding REVS (department) of the State Enterprise "Vodokanal of St. Petersburg". Malfunctions of water sources discovered while extinguishing fires are recorded in the inspection book and a telephone message is sent to the REVS (department) of the State Enterprise "Vodokanal of St. Petersburg" indicating the time frame for elimination. In case of non-compliance with the State Fire Regulations and telephone messages within the established time frame, those responsible for fire-fighting water supply in hazardous production facilities are obliged to apply to the heads of REWS (departments) of the State Enterprise "Vodokanal of St. Petersburg" the rights provided for in the "Regulations on State Fire Supervision".

The REVS (department) of the State Enterprise "Vodokanal of St. Petersburg" informs the PC in the form of a telephone message indicating the timing of their re-inspection about the elimination of malfunctions of fire hydrants. For a repeat inspection, the mobile brigade of the AVR REWS (department) of the State Enterprise "Vodokanal of St. Petersburg" goes with a representative of the fire department (senior firefighter), who records the results of eliminating defects with an indication of the date in the fire-fighting water supply inspection book and reports them to the deputy head of the fire department.

Inspections of on-site fire water supply.

For high-quality study and control over the state of the fire-fighting water supply, economic objects (organizations, institutions) are assigned to guard chiefs by order for a period of half a year. Guard chiefs are personally responsible for timely monitoring of the condition of fire-fighting water supply sources at the facilities assigned to them within the established time frame.

All defects in fire-fighting water supply sources identified at economic facilities during the inspection period are entered into the Inspection Book. If malfunctions in water sources are discovered during an inspection, the chief of guard draws up an administrative protocol against the responsible persons responsible, which is transferred for analysis and issuance of a decision to the State Fire Inspectorate inspector assigned to the facility. A consolidated list of water sources that have not been repaired for 3 or more months should be sent in the form of an “alarm signal” (Appendix No. 3 “Instructions...”) to the DSPT UGPS

Information about malfunctions of water sources at facilities served by the State Fire Inspectorate of other ministries and departments should be sent, signed by the head of the hazardous production facility, to departmental inspections.

The inspection staff of Gospozhnadzor bears personal responsibility for monitoring the progress of troubleshooting fire water supply sources at assigned facilities.

Information from economic entities (organizations, institutions) about the implementation of work to eliminate defects in water sources must be checked on site; if the water source is in good condition, a corresponding entry is made in the inspection book and a date is set.

All information about the state of city and facility sources of fire-fighting water supply, obtained during the period of inspections, during fire extinguishing, fire-tactical exercises and classes (PTU, PTZ), is entered into the Water Supply Inspection Book by the senior firefighter on duty during the inspection of the water source, or immediately after returning to the unit from the fire, vocational school (PTZ). When troubleshooting a water source, an entry in the Inspection Book is made after a repeat (control) check of its condition by the senior fireman on duty. The book of fire-fighting water supply checks is filled out monthly by the deputy head of the fire department immediately before drawing up an operational report on the state of the fire-fighting water supply in the protected area. If the condition of the water source has not changed for the current month, then the information from the previous month is entered into the corresponding column of the Inspection Book and a signature is placed.

Based on the entries in the inspection book, the person responsible for fire water supply in the PCH monthly, before the 25th day, makes:

 information about the malfunction of the fire-fighting water supply in the area where the PCH departs (Appendix No. 5 “Instructions...”), which are transported one copy at a time on the main vehicles;

 an operational report on the state of fire-fighting water supply in the protected area (Appendix No. 2 “Instructions...”), which is transmitted to the Duty Department of the Central Control Center of the UGPS on the 26-27-28-29 of each month on the day of duty of the second guard.

Methodology for testing water supply for water loss

Water supply networks are tested during hours of maximum water consumption, for example: in residential buildings - from 7 to 9 am; at industrial facilities, if there is a drinking water supply - during the lunch break; for industrial and fire-fighting water supply systems - depending on water consumption for production processes.

The technique for testing water supply networks for water loss is to:

 establish the existing water pressure and flow rate in the water supply network;

 determine what pressure and water flow should be according to standards;

 compare the existing water pressure and flow rate with what should be according to the standards and draw a conclusion about their compliance.

Test for water loss of low pressure water pipes.

Testing for water loss of low-pressure water pipes can be carried out using imported pumps in the following sequence:

The estimated fire water consumption for external fire extinguishing is determined in accordance with the requirements of SNiP 2.04.02-84 "Water supply. External networks and structures."

Determine how many motor pumps will be required to select the required water flow from the external network, for example: Qnorm=90 l/sec, for testing n=90/40=3 pumps of the PN-40U brand will be required

Fire pumps are installed on the most unfavorably located hydrants and connected to the pump using soft hoses (to prevent pumping out water under vacuum and thereby prevent contamination of the water supply with groundwater). Rubberized hoses with a diameter of 66, 77 mm (one for each pipe), ending in barrels with large diameter sprays, are attached to the pump pressure pipes.

The water flow from the trunks is determined and the total water flow from the water supply is calculated according to the table below.

Water loss test of high pressure water pipes.

High-pressure water pipes are tested for water loss in two ways:

a) A hose line 120 m long is laid with trunks supplied with a 19 mm spray to the ridge of the tallest building on site. The water flow rate of each jet must be at least 5 l/sec. The total number of design jets that can be obtained during testing is determined depending on the standard fire water flow for a given facility. For example, for a given object, the estimated fire water flow rate is 20 l/sec, then the number of jets that must be obtained during testing should be equal to n=20/5=4 jets. This number of jets can be obtained from one or two hydrants. Having fully opened the valves on the fire pumps and supplied water to the hose lines, use a pressure gauge to determine the pressure at the fire pump.

Then the actual water consumption is determined by the formula:

Q = 0.95 Crl  (Nk - Nstv), where

Krl - the number of hose lines attached to the column;

Nk - pressure on the column pressure gauge;

Hstv - the height of the trunk above ground level.

b) The hose lines specified in the first method are laid, and the trunks are located at ground level. The network is tested at a pressure at the column, the value of which is equal to Hk=Hstv+28. Then the minimum value of the total flow from the hydrant will be equal to:

Q = 0.95 Crl  (Nstv + 28)

The actual flow rate is determined by the readings of the pressure gauge at the column using the formula:

Q = 0.95 Crl  Nk

If during testing, applying the calculated number of jets, it is determined that QfakQnorm, then it is necessary to provide local installations to increase the pressure.

Testing of internal water supply systems for water loss.

To test the internal network, it is necessary to select the highest located internal fire hydrants and those farthest from the input.

Determine the required number of jets and water consumption for internal fire extinguishing for a given building in accordance with SNiP 2.04.01-85 "Internal water supply and sewerage of buildings."

From the taps, lay non-rubberized fire hoses with trunks 10, 15 and 20 m long. To obtain fire jets with a productivity of up to 4 l/sec, fire hydrants and hoses with a diameter of 50 mm should be used, for fire jets of higher productivity - with a diameter of 66 mm.

In order to avoid flooding the premises with water during testing, the trunks must be placed out a window or door outside the building.

Internal fire water supply systems are tested for water loss using one of the following methods:

 change in the radius of action of the compact part of the jet. With this method, when supplying water through the trunks, the radius of action of the fragmented (entire) jet is measured in meters. The radius of the compact part of the jet is 0.8 of the radius of the fragmented jet, i.e. Rк = 0.8 Rp. The resulting radius of action of the compact part of the jet must be compared with what should be according to the standards.

 free pressures of internal fire hydrants must provide compact fire jets with the height necessary to extinguish a fire in the highest and most remote part of the building. The minimum height and radius of action of the compact part of the fire jet should be taken equal to the height of the room, counting from the floor to the highest point of the ceiling, but not less than: 6 m - for residential buildings, as well as in public, production and auxiliary buildings of industrial enterprises, up to 50 m in height ; 8 m - for residential buildings with a height of more than 50 m; 16 m - for public and industrial buildings of industrial enterprises with a height of more than 50 m.

Note: testing the internal water supply for water loss must be carried out with the simultaneous supply of the calculated amount of water for external fire extinguishing.

Features of fire-fighting water supply in waterless areas

Sometimes, due to the insufficiently developed city water supply system, there is not enough water for firefighting. In these cases, the head of the first fire department to arrive at the fire must: organize the supply of fire nozzles in critical directions, ensuring extinguishing in other areas of the fire by dismantling structures and creating the necessary gaps; take measures to determine the location of the nearest water sources, from which additional water can be obtained by installing fire fighting equipment for pumping operations or transported by tankers, fuel trucks, watering machines and other equipment. When extinguishing a fire by supplying water, you should use such a number of trunks, the uninterrupted operation of which would be ensured by the supply of water.

Identification of urban areas not provided with water for extinguishing fires

The identification of building areas that are not provided with water for extinguishing in the area where the fire department exits must be preceded by work to determine the water yield of the water supply network for fire extinguishing in strict accordance with the regulatory requirements set out in SNiP. When conducting an analysis of water yield for fire extinguishing water supply networks, you should carefully identify areas that do not have water supply networks, pre-built reservoirs (reservoirs), as well as natural water sources (rivers, lakes, ponds, etc.). This information should be put on a tablet of water sources and areas (areas) should be raised with the necessary calculations and schemes for obtaining water (by transportation, pumping) in case of extinguishing fires on them.

Organization of water supply to the fire site in waterless areas

The conditions for successful fire extinguishing require a constant supply of the required calculated amount of water to the fire site. Practical fire service workers are well aware of how important it is to obtain water in a timely manner and in the required quantity to extinguish fires, which is in most cases the main means of fighting fire.

In each fire protection garrison, in the area served by the fire department, based on an analysis of the supply of water for fire fighting, organizational and practical measures must be developed to ensure the organization of timely and in the required quantity of water supply for fire fighting.

If there is a shortage of water, it is very important to take timely measures to supply it from the nearest water sources, using standard fire fighting equipment, as well as national economic equipment. In waterless areas, one should not neglect such sources of water as reservoirs with a water level below the suction height of fire equipment or the lack of reliable access to them. In these cases, it is necessary to organize water intake and supply using hydraulic elevators, water harvesting ejectors and motor pumps. One way to obtain a large amount of water through existing water supply systems that have insufficient pressure and minimal flow is to turn on additional backup booster pumps, and in case of more complex fires, to turn off individual sections of the water supply network to direct additional water to the fire site.

When organizing the supply of water by tanker trucks, one must keep in mind that the smooth and organized operation of tanker trucks depends on the uninterrupted operation of the first supplied trunk in the main direction of fire spread, and even more so by the further introduction of additional trunks to localize and extinguish the fire. To reduce the time when filling tank trucks with water and emptying them at the fire site, it is necessary to organize a tank truck refueling point at the water source, and a water consumption point at the fire site.

At the tank truck refueling point, it is advisable to install vehicle pumps and motor pumps; at the point of water consumption there are tankers into which water is poured to ensure the constant operation of fire nozzles.

The number of tank trucks Nc required to supply water and ensure uninterrupted operation of the shafts is determined with sufficient accuracy for practice by the formula

where is the travel time of tank trucks to the water source and back, min; - time for filling tankers with water, min; - tanker emptying time, min; - number of reserve tank trucks (accepted depending on the availability of equipment).

The travel time to the water source and back to the fire site is determined by the formula

where L is the distance from the fire to the water source, km; - average speed of the tank truck km/h.

The tank truck refueling time is determined by the formula

where is the capacity of the tank, l; - flow rate of the pump that fills the tanker (water flow from the fire pump) l/min.

The tank emptying time is determined by the formula

where is the total productivity of the shafts supplying water to the fire, l/s.

Using jet pumps to extract and supply water to the fire site

To collect water from natural water sources that have unfavorable conditions for fire trucks to access (steep or swampy banks), you can use jet pumps - hydraulic elevators and water harvesting ejectors. The operation of these pumps is based on the principle of ejection, created by the energy of the working medium. The working medium for hydraulic elevators and ejectors is water supplied from fire truck pumps or fire motor pumps.

As the practice of extinguishing fires in areas with poorly developed water supply shows, in the absence of access roads to sources of natural water supply or with unsatisfactory terrain, hydraulic elevators can be used to collect water from open water sources with a lifting height of up to 20 m, located at a distance of up to 100 m with a water layer thickness not less than 5 cm.

Currently, G-600 hydraulic elevators are widely used; EV-200 water harvesting ejectors, which have the same purpose as G-600, are less commonly used.

The G-600 hydraulic elevator consists of a vacuum chamber and a suction grille; Using bolts, an elbow and a diffuser with a mixing chamber and stand are attached to the vacuum chamber. The conical nozzle is screwed onto the elbow fitting and placed inside the vacuum chamber. To connect the pressure hoses to the hydraulic elevator, there are coupling heads at the ends of the diffuser and elbow.

The principle of operation of the hydraulic elevator is as follows: under the pressure created by the pump, water flows to the hydraulic elevator. A stream of water coming out of the nozzle creates a vacuum in the diffuser. Under the influence of atmospheric pressure on the surface of the reservoir, water from it rushes through the grate into the vacuum chamber, then into the diffuser, where it mixes with the water supplied to the hydraulic elevator.

In the practice of extinguishing fires using hydraulic elevators, the following schemes are most widespread.

1. Scheme of water intake by hydraulic elevator systems using suction hoses. The operation of this scheme is carried out when it is necessary to obtain significant water flows to extinguish a fire. Water is taken from the tanker through the suction hose by a pump, and the working part of it is supplied through the pressure pipe and then along the pressure fire hose to the hydraulic elevator, from which, together with the ejected water, it enters the tank along the return line of the fire hoses. The ejected part of the water thus obtained is directed through the second pipe of the pump to extinguish the fire.

2. Scheme of water intake by hydraulic elevator systems using a stationary pipeline. In this case, water from the tanker is supplied through a pipeline connecting the tank to the suction cavity of the pump. In this case, the tank tank capacity plays the role of an intermediate tank, ensuring stable operation of the hydraulic elevator system.

3. Scheme of water intake by hydraulic elevator systems using a water collector. The water collector is installed on the suction pipe of the pump, and the tank tank is used only to start the system. After startup, the tank is turned off and does not participate in the operation of the system. Working and ejected water enters directly into the pump.

When supplying water to the fire site, it is necessary to maintain pressure on the pump, which depends on the ejected flow rate and the height of the water rise from the source. The pressure value when working with the G-600 hydraulic elevator is taken according to the table.

To determine the possibility of putting the hydraulic elevator system into operation, compare the water supply in the tank tank tank (V, l) with the amount of water required to start it. This quantity is determined by the formula

where are respectively the volumes of water in the inlet and outlet hose lines, l, determined by the formula (l is the length of the hose line of the system, m; 2 is the water reserve coefficient (for one hydraulic elevator system)).

or according to the table

Number of hydraulic elevators	Diameter of hose lines, mm	Length of hose lines, m
Some EV-200

If the amount of water in the tank tank remains less than necessary, it must be replenished to the required amount. During normal operation of the hydraulic elevator, it is capable of supplying at least 600 l/min of water, which is enough to operate one barrel with a spray with a diameter of 19 mm or two or three barrels with a spray with a diameter of 13 mm. The uninterrupted operation of the hydraulic elevator system requires all personnel to constantly monitor the correct operation of all sections of the system and take urgent measures to eliminate detected faults.

Below are the most common malfunctions that can lead to system shutdown and how to resolve them.

Malfunctions

Elimination procedure

There is not enough water in the tank The hydraulic elevator nozzle is clogged Suction grid clogged The suction grid of the hydraulic elevator is not immersed in the reservoir The hose lines leading to and from the hydraulic elevator have creases A sharp drop in engine speed Flattening of hydraulic elevator system hoses Clogging of hydraulic elevators Exceeding the maximum suction height or the distance from the installation site of the car pump to the water source Rupture of hoses in the hydraulic elevator system

Fill to required quantity Disassemble and clean the nozzle Clean the grate Immerse the grate in the pond Adjust sleeves to avoid wrinkles Maintain the desired engine operating mode, preventing a decrease in speed Clean the hydraulic elevator from foreign objects Before deploying the hydraulic elevator system, it is necessary to determine the maximum distance from the installation site of the car pump to the water source and the suction height Damaged hoses must be replaced with serviceable ones or repaired by applying clamps

The supply of water to the fire site by pumping is used mainly at a significant distance from the water sources of the fire object. This is explained by the fact that one pump installed on a water source is not able to create pressure sufficient to overcome pressure losses in the hose lines and to create working jets of fire trunks directly at the site of the fire. For this reason, a pumping method is used, which consists in the fact that water from the water source to the fire site is sequentially supplied from one pump to the next, and the last one in the pumping circuit supplies water directly through the working lines to extinguish the fire.

The practice of using this method of transporting water to supply it to the source of a fire is quite well established and, with the precise action of the crews of fire trucks, ensures the successful extinguishing of fires that occur in areas with an insufficiently developed water supply.

Depending on the terrain, the location of water sources, the amount of water supplied to extinguish the fire, the availability and tactical and technical data of the main fire engines in service with fire departments, the methods of pumping water can be different.

Method of pumping from pump to pump

According to this method, water is supplied from a motor pump installed on a water source to the suction pipe of the next pump, from which water is supplied to the next pump or directly to fire nozzles located at combat positions (near the fire site).

Method of pumping water using an intermediate tank

In this case, from an autopump installed on a water source, water is supplied through pressure hoses into a tank (reservoir) or into a reservoir, from which it is taken by subsequent autopumps and supplied to other containers or directly to fire nozzles located at combat sites.

The third method of pumping water is similar to the second

The fire tanker tank serves as an intermediate tank. Water from a truck pump installed at the water source is supplied to the tank tank tank through a hose line, the pump of which supplies water through the hose lines to the tank of the next tank truck or to the combat areas.

When preparing fire trucks for pumping work, the following conditions must be observed:

 a fire truck pump with the best technical characteristics (pressure, flow) must be installed on a water source;

 ensure the synchronization of pump operation to avoid sudden pressure changes of individual pumps and flattening of pressure fire hoses, and, consequently, stopping the supply of water to the fire site. In this regard, it is necessary to ensure prompt communication between drivers servicing car pumps in order to promptly respond to changes in pressure values ​​and immediately restore normal operation of the pump and the entire system;

 provide a supply of fire hoses for sections of the pumping line for quick replacement in case of rupture of hoses in the working line;

 on fire truck pumps, constantly maintain a pressure that ensures stable operation of the entire pump-hose system.

Using the laws of hydraulics and formulas derived taking into account its requirements, as well as local conditions, it is possible to practically calculate any pump-hose system, which, with sufficiently high accuracy for practice, can be used to extinguish fires in real conditions. These calculations and the selection of the most appropriate schemes for using pump-hose systems must be carried out in advance for each waterless section of the fire department departure area. After completing this work, all calculation and graphic materials are drawn up in the form of plans (cards) for extinguishing fires in each specific waterless area and are used, if necessary, when extinguishing fires that occur in these areas. In order for fire brigade personnel to obtain the skills to bring pump-hose systems into readiness for work in fire brigades, it is necessary to regularly organize and practice practical techniques and actions on the ground using basic fire-fighting and special equipment provided for these purposes.