We have a situation on a large system that has the jockey pump piped to the suction side of a 10" pressure reducing valve. The fire pump churns at 210psi and the prv is set for 175psi discharge. Because there is no volume of pipe prior to the prv my jockey pump cycles on and off every 5-7 seconds which will eventually damage the jockey controller contactor and cause failure. We tried moving the sensing line from the jockey line to the bulk main which did not change the operation of the jockey pump. We contacted Cla-Val, the manufacture of the prv, and they suggested piping the jockey pump to the discharge side of the prv. They said the pressure is bleeding through the 1/8" orifice of the CRL valve which is located on the trim of the prv. NFPA 20 recommends setting on/off pressures at churn of fire pump which in this case is 210psi. If we pipe the jockey after the prv and set off pressure at 175psi and on at 165psi and the on pressure of the fire pump at 160psi this will produce a 50psi hammer. What would be the best way to correct this problem?
Thanks, Dewayne _______________________________________________ Sprinklerforum mailing list http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
