Fire Water Jockey Pump Configuration
Fire Water Jockey Pump Configuration
(OP)
In most firewater systems I've seen, the jockey pump only kicks in when required to re-pressurise the firewater mains. However, I've just been presented with a set of P&IDs for a very large fire system, for a very large plant, in which it is implied that the jockey pump operates continuously with a continuous kickback to the fire water tank. This kickback is flow controled using a FCV and FIC upstream of the offtake.
Is this normal, and if so what are the advantages of doing this over having the pump kick in when required?
As far as I can see neither NFPA, nor any other standard says anything other than the duty of the Jockey pump is to maintain system pressure.
Is this normal, and if so what are the advantages of doing this over having the pump kick in when required?
As far as I can see neither NFPA, nor any other standard says anything other than the duty of the Jockey pump is to maintain system pressure.
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RE: Fire Water Jockey Pump Configuration
just my thoughts.
RE: Fire Water Jockey Pump Configuration
RE: Fire Water Jockey Pump Configuration
I noticed that in very large underground fire mains systems, the pressure in the fire mains can vary constantly. The variation can be 0,5 - 1,0 bar as far as I have seen. When that happens, I can imagine that it can be better to keep the jockey pump working all the time, and to regulate the pressure via a pressure relief valve with a outlet to the water storage. I've never seen this but this can be the reasing that the engineer has chosen this way to control a constant pressure. The disadvantage are the energy costs and the maintenance of the the jockeypump because is has that many working hours. The advantage is a more constant pressure in the systems and less false alarms because of the (slight) water hammer that can take place when a jockey pump starts.