A fire water pump is a fire safety system that maintains pressure in the system (usually in the range of 8-10 barg) when the main hydrant or sprinklers are open. It is automatically controlled and triggered by pressure sensors when the water supply pressure drops below a predetermined set point.
Choosing the right size fire pump depends on local codes and design criteria for your facility. For example, if you have a lot of leakage in your underground piping, you will need to select a larger pump to compensate for the loss of pressure. If your building is very tall, you will need a higher discharge pressure in order to reach the top floor.
You must also consider the system flow rate and pressure requirements. The pump must be capable of handling the full rated flow while maintaining its pressure and delivering the firefighting water needed to extinguish the sprinklers or hydrant. The sizing of fire pumps can be complicated and requires the use of a pump performance curve to determine how well the pump will perform at different flows and discharge pressures.
Generally, the best way to ensure that your fire pump will meet the needs of your system is to choose a model with flame plating on the impeller. This is a process that applies tungsten carbide to the wear surfaces of the impeller. This is much harder than hard chrome and outwears normal filing. It also helps prevent premature wear on the impeller bearings and seals.