What we do in SD is even more challenging, in that they want more than the minimum standard of performance but not too much more. We don't just design for the minimum - it's 115 PSI here - but we have a maximum of 125 PSI on the back side of that equation. So we use reducing valves up to the level of churn exceeding 175 PSI and then restricting valves after that, all the way to the roof. Valves are set at 115-125. Another local requirement is that all valves have to be field-adjustable type and the local FD trains firefighters on how to adjust and best use the valves. Between the engineer pumping the FDC, the building fire pump and the adjustable valves, SDFD's finest can get a wide range of residual pressure at flows from 150-300 GPM. It's not the cheapest or simplest design, but it makes them very, very happy.
Steve Leyton Protection Design & Consulting San Diego, CA -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Jerry Costello Sent: Wednesday, August 12, 2009 2:27 PM To: [email protected] Subject: RE: High Rise Standpipes Thanks Steve, I just hope the valve mfgers are working on a redesign taking into account this 125 psi as well as possibly the 300 flow requirement and reduce the differential. Seems crazy to put PRVs on the roof... Jerry M Costello set Advance Fire Protection Ph 714-526-2231 Fax 562-691-5482 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Steve Leyton Sent: Wednesday, August 12, 2009 2:04 PM To: [email protected] Subject: RE: High Rise Standpipes That's not my preferred method and NFPA 14 requires that if you do that - it is permissible - that you configure a manifold of at least two PRV's arranged so that the failure of one can be bypassed. Additionally, since they have minimum functional flow rates, you will have to put two more PRV's of a smaller diameter on the header, so account for the much lower flow rate of a single sprinkler or two or three. I personally prefer the "point of connection" valves because if one should start acting up or fail entirely, a firefighter can simply shut it down and get water from one level above or below the fire floor. Master PRV's have a global impact on the entire standpipe or zone. I should add: The foregoing is my opinion only and does not necessarily represent the opinion or intent of the NFPA 14 Technical Committee on Standpipe and Hose Systems. Steve Leyton Protection Design & Consulting San Diego, CA -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Jerry Costello Sent: Wednesday, August 12, 2009 1:58 PM To: [email protected] Subject: RE: High Rise Standpipes Thanks again Steve, I have looked at a lot of valve curves recently and I agree that there are differences especially between factory set and field adj.type. Unfortunately we cannot use factory set in LA City anymore and none of the field adjustable that I have reviewed allow for the switch to standard valves, because of the pressure differential problem previously described. Have you (or anyone) ever installed a 4" or 6" pressure regulating valve such as the ClaVal 90G-21 vertically on your standpipe at the point in height where churn pressure break in elv.reaches 175psi. My thought is to use this larger pressure regulating valve to reduce standpipe pressure to 165 where standard valves can be utilized the rest of the way thru the roof. This should greatly reduce the needed pump pressure required keeping pressure down to 300 psi or below. Jerry M Costello set Advance Fire Protection Ph 714-526-2231 Fax 562-691-5482 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Steve Leyton Sent: Wednesday, August 12, 2009 1:27 PM To: [email protected] Subject: RE: High Rise Standpipes I'm not sure what make/model of valve you're considering, but there are a few out there with as little as 50 PSI differential. Check out the Wilkins ZW 4000 series; it's a "factory set" type valve (not field adjustable), but you can change out the restrictors in the field which makes them pretty flexible to commission. If you need field-adjustable type, go with the Z 3000 series. I think the Elkhart URFA valves - which are hyper-trick and very compact and can be adjusted both flowing and closed - are a supremely good product, but they do have a very high differential. Don't judge all reducing hose valves by the curves of just one or two. Steve Leyton Protection Design & Consulting San Diego, CA -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Jerry Costello Sent: Wednesday, August 12, 2009 8:47 AM To: [email protected] Subject: RE: High Rise Standpipes Thanks Steve I really appreciate your input but I still do not follow , the Potter Roemer restricting valves are only listed for 175 psi inlet. As I see it I still have the same issue of having a needed residual 230 p...@300gall to get 1...@300 (or 250 depending on city) out when using the regulating valve (non-reg valves not allowed in LA). In a standard 12' floor elevation change +5psi loss you cannot get from a regulating to restricting in one floor because of the 175 listing on the restricting valve. Note I need more than 175 psi up thru approx 4 floors. Jerry M Costello set Advance Fire Protection Ph 714-526-2231 Fax 562-691-5482 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Steve Leyton Sent: Wednesday, August 12, 2009 7:41 AM To: [email protected] Subject: RE: High Rise Standpipes Jerry: There is invariably a break where the static (churn) pressure drops below 175 in the standpipes, but above which you may still want pressure regulation. This is exactly how we do it in Lo-Cal and you want to look into a pressure RESTRICTING hose valve. They are much less expensive than reducing valves, and very simple to adjust in the field. Check out the Potter-Roemer catalog. Steve Leyton Protection Design & Consulting San Diego, CA -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Jerry Costello Sent: Wednesday, August 12, 2009 7:33 AM To: [email protected] Subject: High Rise Standpipes We are beginning to see more and more authorities require the class 1 outlets to supply 125 at 500 at roof and in the city of LA 125 psi at 300 gpm at all class 1 outlets. I seem to be finding that once you reach a building height sufficient to require sprk/hose regulating valves then they need to be installed all the way thru the roof. This because the adjustment of the valves for the 125 psi setting does not allow you to switch back to standard non regulating valves once you get to needed elevation as you could in the past. Since the settings for the adjustable valves require approx 230 psi/residual in to get 125psi residual out, we are seeing what seems to me a pump sized much larger than should be required. I have thought of installing pressure regulating valves on the main vertical standpipes at a certain height, but not sure this is good practice. Any thoughts? Are mfg companies addressing this issue on a possible redesign? Thanks for your time Jerry M Costello set Advance Fire Protection Ph 714-526-2231 Fax 562-691-5482 __________ Information from ESET NOD32 Antivirus, version of virus signature database 4329 (20090812) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 4329 (20090812) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com _______________________________________________ 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) _______________________________________________ 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) __________ Information from ESET NOD32 Antivirus, version of virus signature database 4329 (20090812) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 4330 (20090812) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com _______________________________________________ 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) _______________________________________________ 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) _______________________________________________ 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) _______________________________________________ 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) _______________________________________________ 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)
