Water supply and regulation

A fire tank is a container for storing a liquid for localizing fires. This equipment is provided in cases where water intake from a water supply source is economically unprofitable, technically impracticable, or its volume is insufficient to eliminate a fire.

Such tanks are installed in the fire extinguishing engineering system at enterprises that have signs of increased danger in the production process. The same category also includes gas stations, oil depots and warehouses for fuels and lubricants (POL).

Location rules

The placement of containers is made based on the presence of buildings and structures, taking into account SNiP, avoiding exceeding the distances:

• with installed motor pumps - within a radius of 100 to 150 m;
• during the operation of auto pumps - up to 200 m.

The distance to buildings of I and II degrees of fire resistance is no closer than 10 m; to buildings III; IV; V degrees and open warehouses of fuels and lubricants - 30 m. The equipment is located in such a way that the supply of the reagent can be carried out at any time of the day and in the required quantity to extinguish both internal fires and external ignition.

Design features

Structurally, a fire tank is a single-walled vertical or horizontal rectangular or cylindrical tank with a conical bottom. Horizontal fire reservoirs have a capacity of 5 cubic meters. up to 100 cubic meters

Vertical water storage is much more capacious - 100-5000 cubic meters. In addition, when installed, this design allows for space savings.

Fire tanks are made of sheet steel with an internal anti-corrosion coating (or without it). Steel grades for production are selected in accordance with the climatic characteristics of the installation region. Internal annular stiffening diaphragms provide additional strength to the body.

Installation of the structure is carried out on the base. For it, road blocks, foundation slabs, a concrete pad or special metal supports at a height of 3 to 7 meters from the earth's surface can be used. The tank is fastened with anchor bolts through the holes in the base. Installation can be above ground or underground.

Ground structures in harsh climates require additional thermal insulation of the tank:

• installation of a coil with a coolant supply directly from the heating main or from the boiler room;
• installation of electric heating of system pipelines and the tank itself by means of fiberglass heaters;
• organization of forced circulation of liquid in order to prevent freezing.

Underground structures have an advantage over tanks located on the surface in terms of space saving and the absence of the need for insulation or heating of the inner cavity in winter. An underground fire containment liquid storage facility can only have a cylindrical shape.

The disadvantage of the underground location is considered to be a complex of expensive earthworks, the need for preparation and reliable fastening of the base. In addition, external waterproofing is required as protection from groundwater, based on a multi-layer coating with epoxy paints and varnishes or polymers.

Filling takes place with the help of pumps through a hatch provided in the structure.

Kit structure

In accordance with the design, the fire tank kit includes ladders or brackets for lifting and lowering personnel, observation platforms, sensors and liquid level control devices.

In the design of the entire system, according to modern requirements, it is necessary to provide the following equipment:

1. filler pipe. The tank is filled through a shut-off valve-pipeline;
2. drainage well. It is needed to fill a fire engine with water. It connects the overflow reservoir to the storm sewer;
3. suction inlet with valve. Through it, filling with fire pumps takes place;
4. a drain pipe with a shut-off valve for planned, emergency drains, as well as for draining during inspection, control or repair work;
5. overflow pipe. It is connected to a drainage well and sewerage system in case of an overflow of the reservoir.

The main factors in the selection and arrangement of a structure for fire extinguishing are the number of possible fires and their duration in time. Therefore, for the correct selection of the tank, an approximate number of estimated probable fires for a certain period of time is determined. The length of time planned to eliminate the fire is also calculated.

Then, the optimal volume of the fire tank is established - subject to the provision of fire extinguishing water from internal fire hydrants, taking into account the need for sprinkler and deluge installations that are not provided with their own reserve stocks. When calculating, the possibility of replenishing the stock of the fire tank during a fire from the general water supply system is allowed.

The number of required containers at a given site is determined. The calculation should be such that if one fails, the remaining ones should be filled with at least half of the emergency volume of water.

The levels of fire volumes in all tanks of the fire extinguishing system must be maintained at the same levels - both at the lowest and at the highest points.

It is necessary to provide free access to the tanks and wells for fire trucks on a hard road surface.

Water supply and regulation

In water supply systems, water towers, air-water boilers (hydropneumatic installations) that accumulate water volumes to regulate the operation of the entire system, as well as reserves for fires are referred to as regulating and reserve water storage facilities. The regulation of reserves consists in the accumulation of water in water towers when supplied in excess and withdrawn from it when there is a shortage in the general water use system.

A reserve of fire water volume is provided when it is technically impossible to obtain the optimal amount of water from the water supply system to extinguish the fire. At the same time, there is a method for calculating the emergency reserve of the fire-prevention volume. Provides the creation of an emergency reserve for localizing the source of fire for up to 3 hours at a flow rate of 25 liters per second and up to 6 hours at a flow rate of more than 25 liters per second.

The consumption of the inviolable supply of the water tower is allowed only upon receipt of a fire notification.

To extinguish fires, the required pressure of the supplied water must be ensured. Heads are calculated based on the conditions for creating jets from fire hydrants or the operation of special installations inside buildings.

The equipment of storage tanks and water towers must ensure the constant availability of an inviolable supply of water, even if in some cases the pumping units are forced to work beyond the established time schedule.

(No ratings yet)