The electric fire pump is mainly used for the pressurized water supply of the fire protection system. It can also be applied to industrial and urban water supply and drainage, high-rise building pressurized water supply, long-distance water supply, heating, bathroom, boiler cold and warm water circulation, pressurized air conditioning and refrigeration system water supply and equipment support. There are often customer feedback fire pumps that have no pumping water, and the reasons are summarized in 4 points.
First, the internal resistance loss of the pipeline is too large:
The water supply pipeline is too long, the water pipe bends many joints, and the excessive loss of water flow in the pipeline can also lead to insufficient pressure and flow. Under normal circumstances, the 90 degree bend is more resistant than the 120 degree bend, and the lift of each 90 degree bend is about 0.5~1 meters. The resistance of each 20 meter pipeline can cause the head to lose about 1 meter of lift (ie 0.01MPa pressure). ).
Second, the motor speed is too low:
1. If the fire pump motor is damaged, it can be equipped with another motor. If the motor speed is insufficient, the pump will have less flow and the pressure will decrease.
2. If the belt drive pump is used, the long-term use will cause the belt to wear and loose, and the slip phenomenon will occur, thus reducing the speed of the pump.
3. The impeller wear is severe, the impeller is damaged, the vane is worn or damaged, and the pumping is insufficient.
Third, the installation location is too high, resulting in too high aspiration:
The vertical distance between the water source and the installation position of the fire pump is too high to exceed the maximum suction of the pump. The negative pressure generated inside the pump cannot press the water to a certain height. Generally, the suction stroke of the pump is between 3 and 8.5 meters. When installing the pump, it is not necessary to simply ignore the pump suction stroke. Otherwise, not only will it not be able to absorb water, but it may also cause severe cavitation damage to the pump fittings.
Fourth, the inlet pipe leaks or the pump industry still has air for exclusion:
1. If the centrifugal pump is not filled with enough water before starting, the fire pump starts up so that a high vacuum cannot be formed, so that the water in the pool cannot be pressed into the pump body. If it cannot be started after filling with water, you can try to open the pump. The exhaust valve deflates the pump.
2. The mechanical seal of the pump has been worn out due to long-term use, causing a large amount of water to be ejected from the gap between the mechanical seal and the pump shaft bushing. The external air enters the pump from these gaps and the vacuum cannot be formed.