IS 38 psi the municipal residual pressure? At what flow rate as compared to the pump’s rating?
Craig Prahl | Jacobs | Fire Protection SME – EV, AM, DC, Special Hazards [email protected]<mailto:[email protected]> | www.jacobs.com<https://urldefense.com/v3/__http:/www.jacobs.com/__;!!KZTdOCjhgt4hgw!-_khxU8gU0_6jc895I7kRbnU8JghRDsWgqOblZ4jr7Qp2IVbR30VYw_hWvNFtphnl0uWpB9KIvbYi1pvZz4$> 1041 East Butler Road Greenville, South Carolina 29606 CONTACT BY: Phone 1-864-676-5252, Email or MS TEAMS From: Fpdcdesign <[email protected]> Sent: Tuesday, June 24, 2025 12:17 PM To: Discussion list on issues relating to automatic fire sprinklers <[email protected]> Subject: [Sprinklerforum] Re: [EXTERNAL] Backflow turbulence The water supply tested in the street to 38 psi with less than 5 ft elevation to the pump room. The suction pressure they are getting during the pump test is 15 Todd Williams Fire Protection Design/Consulting Stonington, CT 860-608-4559 On Jun The water supply tested in the street to 38 psi with less than 5 ft elevation to the pump room. The suction pressure they are getting during the pump test is 15 Todd Williams Fire Protection Design/Consulting Stonington, CT 860-608-4559 On Jun 24, 2025 at 11:39 AM, <Craig Prahl<mailto:[email protected]>> wrote: Are suction pressures low due to the water supply? Since there is a BFP, I assume you’re drawing from a city service, correct? Got any data on that system? Craig Prahl | Jacobs | Fire Protection SME – EV, AM, DC, Special Hazards [email protected]<mailto:[email protected]> | www.jacobs.com<https://urldefense.com/v3/__http:/www.jacobs.com/__;!!KZTdOCjhgt4hgw!-_khxU8gU0_6jc895I7kRbnU8JghRDsWgqOblZ4jr7Qp2IVbR30VYw_hWvNFtphnl0uWpB9KIvbYi1pvZz4$> 1041 East Butler Road Greenville, South Carolina 29606 CONTACT BY: Phone 1-864-676-5252, Email or MS TEAMS From: Fpdcdesign <[email protected]<mailto:[email protected]>> Sent: Tuesday, June 24, 2025 10:45 AM To: Sprinklerforum <[email protected]<mailto:[email protected]>> Subject: [EXTERNAL] [Sprinklerforum] Backflow turbulence I am working on an untestable fire pump with an “N” shaped RPZ in the suction line. They (just) have the 10X diameter distance on the feed, but the suction pressures are very low (15 psi). It seems that an “N” shaped device would create a lost I am working on an untestable fire pump with an “N” shaped RPZ in the suction line. They (just) have the 10X diameter distance on the feed, but the suction pressures are very low (15 psi). It seems that an “N” shaped device would create a lost more turbulence than a standard straight one. Consequently, should the distance of straight pipe requirement be greater for this arrangement? Todd G Williams, PE Fire Protection Design/Consulting Stonington, CT 860-535-2080<tel:860-535-2080> (ofc) 860-554-7054<tel:860-554-7054> (fax) 860-608-4559<tel:860-608-4559> (cell) ________________________________ NOTICE - This communication may contain confidential and privileged information that is for the sole use of the intended recipient. Any viewing, copying or distribution of, or reliance on this message by unintended recipients is strictly prohibited. If you have received this message in error, please notify us immediately by replying to the message and deleting it from your computer. _________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org<https://urldefense.com/v3/__https:/lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org__;!!B5cixuoO7ltTeg!BXROdjlCH_HD1dZflm5fL36y1RAbtph6W8gzx597Os4quHJL6bZFbNK9RNGmC-iqtDj9Jm6hwWx28cWKWCAuUw$> To unsubscribe send an email to [email protected]<mailto:[email protected]> ________________________________ NOTICE - This communication may contain confidential and privileged information that is for the sole use of the intended recipient. Any viewing, copying or distribution of, or reliance on this message by unintended recipients is strictly prohibited. If you have received this message in error, please notify us immediately by replying to the message and deleting it from your computer.
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