Method of selecting the flow of stabilized pressure pump

Method of selecting the flow ofstabilized pressure pump
The pressure stabilizing pump is a kind of fire pump, which is used to ensure the pressure of the water supply system of the active sprinkler system and the fire hydrant is stable, so that the water pressure of the system is always at the required pressure. Once the water from the sprinkler or the fire hydrant comes out, the water volume and pressure required for satisfying the fire water can be released. Although both the pressure stabilizing pump and booster pump are pressurizing equipment, the pressure stabilizing pump operates when the nozzle and fire hydrant have not flowed out, and the booster pump operates when the nozzle and fire hydrant have already flowed out of water, while the water pressure of fire water is insufficient, so it is necessary to add water pressure.
The current code of China, Code for Fire Protection Design of High rise Civil Buildings (GBJ50045-95) (hereinafter referred to as the "High rise Code"), has the following rules for booster equipment (including stabilized pressure pumps): "7.4.8.1 The water output of booster pumps should not be greater than 5L/s for the fire hydrant water supply system and 1L/s for the main sprinkler system." This rule is conditional, one of which is that there is no pneumatic water tank in the fire water supply system; The second condition is that the small leakage of the indoor fire water supply system is mainly at the sealing part of the pump. The rules in this article do not mean that the stabilized pressure pump shall be determined according to this flow under any conditions.
The booster pump referred to in the High Speed Regulation refers to both the booster pump used for pressurization and the stabilized pressure pump used for pressure stabilization. There is no difference in the provisions of the specification, but in fact, the booster pump and the stabilized pressure pump are different in effect and function, and their flow values are also different.
The booster pump used for nozzles and fire hydrants has already flowed out, but the water pressure of fire water is insufficient, so it is necessary to add water pressure to meet the water pressure demand of fire water. At that time, the flow of booster pump shall cover the flow of a sprinkler or a fire hydrant, that is, not less than 1L/s or 5L/s. However, once the booster pump is started, the main fire pump will also be started subsequently. The effect of the booster pump is not very urgent and necessary.
The pressure stabilizing pump is different from the booster pump, which is used to keep the self spraying system and fire hydrant system under the required pressure working conditions. Once it flows out, it can meet the water pressure and water demand required for fire water. The effect is very significant, so the booster pump referred to in the specification essentially refers to the stabilized pressure pump, especially the stabilized pressure pump of the active water spray rescue system
The flow value of the stabilizedpressure pump depends on many factors, among which the most important ones are:
(1) Type of system When the stabilized pressure pump is used for the self spraying system, consider the water volume of a sprinkler; When it is used in the fire hydrant system, consider the water volume of a fire hydrant.
(2) The flow of the stabilized pressure pump shall be calculated according to the water volume of no more than one nozzle or one fire hydrant when there is no air pressure water tank. When there is an air pressure water tank, the water volume compensation and pressure assurance of the system are implemented by the air pressure water tank. The flow of the stabilized pressure pump only needs to meet the flow demand of the air pressure water tank, that is, the flow of the stabilized pressure pump should consider the elements of the conditioning volume of the air pressure water tank. At this moment, the flow of the stabilized pressure pump shall be calculated and determined according to the total volume of air and water in the tank of the pneumatic water supply equipment and the volume calculation formula of water in the tank. The water output of the pump shall be no less than 1.2 times of the maximum hourly flow of the pipe network when the tank is under uniform pressure.
There is no rule on the necessity of equipping a pneumatic water tank in the High Level Regulation, but there is no pneumatic water tank, and the stabilized pressure pump is frequently started, causing simple damage; With the pneumatic water tank, the frequent starting of the stabilized pressure pump can be alleviated, and the assurance of the system's stabilized pressure working condition can be better performed. However, the cost of adding air pressure water tank is required. Generally, the volume of the air pressure water tank set up in a supporting manner need not be too large, and the volume should be less than 50L.
(3) System scale Quasi high pressure water supply systemThe flow value of the stabilized(or stable high pressure water supply system) with stabilized pressure pump is available in indoor, indoor and outdoor fields. For the indoor quasi high pressure water supply system, steel pipes are used as pipes, and the joints are threaded, flanged or welded. The leakage of the pipe network system mainly occurs at the sealing part of the pump, and the number is relatively limited. For the quasi high pressure water supply system inside and outside the room, because the outdoor pipe material is cast iron pipe, the interface is socket type connection, and the interface seal is rubber ring, the scale of the pipe network is large, and the interface leakage accounts for a proper proportion in the total leakage. After the pipeline construction, the soil shall be recovered immediately. Sometimes, the interface shall be reinforced with mixed soil. Even if there is leakage, it is difficult to take remedial measures. All these indicate that when the quasi high pressure water supply system is selected in the chamber meter, the flow of the stabilized pressure pump should be kept to the extent of satisfaction.