Fire safety technology practice skills: fire pumps

1. Fire pumps should be set up standby pumps, its performance should be consistent with the performance of the working pump, but the following buildings may not set up standby pumps: building height of less than 54m residential and outdoor fire water design flow rate of less than or equal to 25L/s building, indoor fire water design flow rate of less than or equal to 10L / s building.

2. The series connection of fire pumps is to connect the outlet of one pump directly with the suction pipe of another pump and the two pumps are running at the same time, the series connection of fire pumps can increase the head when the flow rate is unchanged. Parallel connection of fire pumps is through two and more than two fire pumps at the same time to the fire water supply system water supply, parallel connection of fire pumps is mainly to increase the flow.

3. When the fire pump pumps water directly from the municipal network, the fire pump should be set up in the fire pump outlet pipe with air isolation backflow preventer. When there is no suction well at the suction port, a rotary flow preventer should be set at the suction port.

4. fire pump suction pipe flare in the lowest effective water level in the fire pool should not be less than 600mm. when the use of rotary flow preventer, the depth of submergence should not be less than 200mm. fire pump suction pipe should be set up on the open-stem gate valves or butterfly valves with self-locking device, but when set up a concealed valve should be equipped with an opening scale and signs; when the diameter of pipe more than DN300, it is appropriate to set up motorised valves. Fire pump suction pipe through the fire pool, should be used flexible casing; rigid waterproof casing should be set in the pump suction pipe flexible joints, and pipe diameter should not be greater than DN150.

5. Fire pumps should be set on the outlet pipe check valves, open-rod gate valve; when using butterfly valves, should be equipped with self-locking device; when the diameter of the pipe is greater than DN300, it is appropriate to set up electric valves (this article and the water inlet pipe compared to the memory).

6. fire pumps should be able to manually start and stop and automatic start, and should ensure that the pump from the start signal to the pump normal operation of the automatic start time should not be greater than 2 min. fire pumps should be set up by the fire pump out of the water mains pressure switch, high fire water tank out of the water mains flow switch, or the alarm valve pressure switch switch signals should be able to start the fire pumps directly and automatically.

7. Fire pump zero flow pressure should not exceed 140% of the design working pressure; when the flow rate for the design of 150% of the working flow rate, the outlet pressure should not be less than 65% of the design working pressure. Fire water supply to the same pump group of fire pumps should be the same model, and the work of the pump should not be more than three.