How to prevent the fire pump
First, from the perspective of prevention, we recommend to open the recirculation pipe when the feed water flow is reduced to a certain extent, so that a part of the feed water flow will return to the deaerator, then there will be enough water in the pump to pass the pump. carry away the heat generated by the friction, keep at a certain temperature from rising to vaporize the feed water.
Second, The choice of fire pump manufacturer. In general, fire pump manufacturers with experience will consider before manufacturing a fire pump. The manufacturer generally specifies an allowable small flow value for the water pump operation (eg, 25% to 30% of the rated flow). This approach can effectively prevent the water from vaporizing due to too little water output. Modern high-speed water pumps generally adopt variable speed regulation, Pump is at low speed when it is small flow, and cavitation phenomenon will not occur easily at low speed, so the allowable small flow is much smaller than the fixed speed water pump.