The '10 Edition has a couple sections on it (4.18.7) so it's allowed, but then you need to comply with 4.18.5.2 & 4.18.5.4 so you can see the discharge or monitor it somehow (flow switch) and 4.18.7.1 to allow a 3/4" or 1" relief valve to atmosphere (depending on flow rating).
Can you not discharge it outside? Dan -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Matt Grise Sent: Tuesday, December 07, 2010 9:12 AM To: '[email protected]' Subject: RE: Pumps - PRV Piped Back to Source You would also need to see how the back pressure would affect the valve's ability to discharge. Matt Grisé PE*, LEED AP Sales Engineer Alliance Fire Protection *Licensed in KS & MO 913.888.0647 ph 913.888.0618 f 913.927.0222 cell www. AFPsprink.com -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Tuesday, December 07, 2010 10:00 AM To: [email protected] Subject: RE: Pumps - PRV Piped Back to Source I've seen PRV discharge sent to storm sewer, sent to ditch and sent back to water storage tank. If it could be re-introduced back into the suction supply, can't imagine what that would do to system hydraulics. Craig L. Prahl, CET Fire Protection CH2MHILL Lockwood Greene 1500 International Drive Spartanburg, SC 29304-0491 Direct - 864.599.4102 Fax - 864.599.8439 CH2MHILL Extension 74102 [email protected] -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Ralphy Henderson Sent: Tuesday, December 07, 2010 10:21 AM To: [email protected] Subject: Pumps - PRV Piped Back to Source Hello, When NFPA #20 requires a pressure relief valve in accord with 5.18.1.1 for a diesel pump is it an acceptable practice to pipe the PRV discharge piping back to the source piping? The source is a city water main. I see NFPA 20 has some info on this but I've never seen it done and was wondering if this would be designed similar to a flow meter test loop? Thanks, Ralph _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.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) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.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) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.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) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.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)
