Fire pumps are an essential part of many water-based fire protection systems. They are used to increase the pressure (measured in psi and bar) of a water source when that source is not adequate for the system it's supplying.A jockey pump, also know as a pressure maintenance pump, maintains the pressure in the fire sprinkler system to avoid non-emergency starting of the main fire pump. This keeps the main fire pump from short cycling, which shortens its life span.