The Selection of Fire Pump

The water that is used for firefighting always needs to be pressurized by fire pump so as to reach the requirement of pressure. And the defects of fire pump set probably cause a great loss that could have been avoided. The function of fire pump should superior than the water in life and production, so it is important to choose a qualified fire pump for firefighting.

The United States stipulates that the maximum flow of fire fighting pump should be 150% of designing flow; the minimum head is 65% of the head of selected work-yard. When the fire pump is closed, the maximum head is 140% of the head of selected work-yard, the pump flow is 1-2L/S, the head is 1.1-1.2 times on the head of fire pump. And a flow meter should be installed on the outlet pipe of fire pump, its range should reach 175% of selected pump flow. A pressure gauge which is up to 89mm in diameter should also be fixed on the outlet pipe. All these parameters can be used as references for designers and purchasers.
The function of pump regulator in supply system is to maintain the normal pressure of fire pump. The pressure of pump regulator can be determined by the pressure of the system, its pressure should normally 0.1Mpa-0.2Mpa higher than the main pump, or 1.1-1.2 times of the main pump. As to the flow of pump regulator, the NFPA20 (1996 Edition) set that the flow of Pressure Maintenan Pumps/Jockey Pumps/Make Up Pumps is not less than the amount of leakage of the system under normal conditions. And the pressure of pump regulator should be sufficient to maintain the system pressure.
According to a survey that the flow of pump regulator is always between 0.5L/S to 2.0L/S in many countries, the water hammer may exist when the pump is closed without pressure tank in the system. The flow of pump regulator is recommended within 1.0L/S-2.0L/S, the pressure of it should be 0.1Mpa-0.2Mpa higher than the main pump, or 1.1-1.2 times of the main pump. And a pressure tank should be installed in system, if not, the controller of pump regulator should be paid more attention to avoid the pump regulator starting frequently because of the effect of water hammer. Only in this way can a fire pump system work normally. And these standards can also be applied to electric fire pump.
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