A jockey pump is a small device that works together with a fire pump as part of a fire-protection sprinkler system. Also referred to as a pressure-maintenance pump, it is designed to maintain high pressure when the system is not in use.
This is to keep the fire pump from running the entire time as well as ensuring the system stays in check.
It can also help prevent the system from damage when there is a fire and water rushes into the pipes. Jockey pumps consist of a three-part assembly.
Fire sprinkler systems consist of pipes with pressurized water in them and heads designed to open when they reach a certain temperature. When the particular temperature is reached and the heads open, the water pressure in the pipes drops to allow water to flow out. This action triggers the fire pump which will then begin to send more water through the pipes to enable the fire to be put out.
Now the jockey pump serves to keep the water pressure in the pipes within a specific range when there’s not a fire. This prevents the sprinklers from going off unnecessarily. Moreover, since pipes are susceptible to leakage over time, the water pressure inside them tends to go down. As soon as the jockey pump senses this, it fills them back up to normal pressure.
On the other hand, should the pressure drop drastically during a fire such that the jockey pump is unable to keep up, the large fire pump will be triggered to send out water for putting out the fire.
The jockey pump also prevents sprinkler systems from being damaged once the fire pump starts sending water. Lack of a jockey pump in a system for purposes of pressure maintenance will result in relatively low pressure. As such, the sudden change in pressure applied when the fire pump starts sending water is likely to damage the system.