Copy that - probably prudent on a calculated project depending on safety factor.
Steve -----Original Message----- From: Tyson Sutherland [mailto:[email protected]] Sent: Monday, August 02, 2021 2:30 PM To: [email protected]; Matthew J Willis <[email protected]> Cc: Steve Leyton <[email protected]>; Ron Greenman <[email protected]> Subject: RE: Flexible hose head connectors on a pipe schedule system Maybe I'm confusing my experiences with revamping pipe schedule systems versus hydraulically designed systems, but I've had several jobs where the AHJ or reviewer ask us to hydraulically prove flex hose assemblies on small relocate jobs. TYSON SUTHERLAND, CET NICET Level III Design Technician Ohio ASSD #8495 2900 Newpark Drive Barberton, OH 44203 888-857-2817 x317 330-600-0697 Cell [email protected] -----Original Message----- From: Sprinklerforum <[email protected]> On Behalf Of Steve Leyton via Sprinklerforum Sent: Monday, August 2, 2021 5:25 PM To: Matthew J Willis <[email protected]>; [email protected] Cc: Steve Leyton <[email protected]>; Ron Greenman <[email protected]> Subject: RE: Flexible hose head connectors on a pipe schedule system BE ADVISED - This email originated outside EMCOR. That fits into what I was saying. A quick review of the actual performance criteria on any project will render a reasonable pad that could be added as I suggested. Whether it's 2 or 5 PSI, I'm still sleeping well by this method. Question for Tyson: What do you mean, "If the AHJ catches on...?" Most wouldn't even be aware of this (it's pretty nuanced) and making that allowance is a completely valid approach. Steve -----Original Message----- From: Matthew J Willis [mailto:[email protected]] Sent: Monday, August 02, 2021 2:17 PM To: [email protected] Cc: Steve Leyton <[email protected]>; Ron Greenman <[email protected]> Subject: RE: Flexible hose head connectors on a pipe schedule system 20-30 seems a bit more than I have seen. We include around that range as part of safety build in without affecting pipe sizing. 14-17 gets you 2 bends on most jobs (Read not FM), which according to multiple field discussions is the most you will ever see. If you consider the fact that a typical return bend is 9 feet equivalent based on the hydraulics table, you are not adding very much more demand to the system. Many jurisdiction though are requiring calcs because as stated, that is outside pipe schedule. R/ Matt -----Original Message----- From: Sprinklerforum <[email protected]> On Behalf Of Steve Leyton via Sprinklerforum Sent: Monday, August 2, 2021 3:11 PM To: [email protected] Cc: Steve Leyton <[email protected]>; Ron Greenman <[email protected]> Subject: RE: Flexible hose head connectors on a pipe schedule system I'm with Obi Ron on this one. I agree that calc's never hurt anything but they can add a fat layer to the work scope if you have to reconstruct as-built conditions to create piping plan for calc's. And it's more complicated that necessary because we can boil it down to the issue of the flex drops simply lowering the net K-factor, which will raise the required starting pressure but will render a similar or lower gross demand in GPM. If a flex drop adds 20-30' of equivalent length, a simple allowance can be made for that in the water supply evaluation criteria found in Chapter 11. Using the more conservative OH values found in Table https://urldefense.com/v3/__http://11.2.2.1__;!!FaxH778!NWq_JPeF_TW_mTYtDzy_S2N8jxI9r0OE1EB74sNHTlmago5FNurCBHQyTsCdZZIpKAKDha4$ , we already have to affirm that there will be 850 GPM at 20 PSI available for a supervised system. If we use 25 GPM as a flow rate, and .2 psi/ft. as for Pf, then a flex drop will impart 4-6 PSI of additional loss from a sprinkler connected directly to the branch. If we allow for some loss in a hard-piped drop and credit that against 4-6 PSI, we can comfortably land on 5 PSI, so I would proffer that affirming 850 GPM at 25 PSI at the riser base meets the intent of https://urldefense.com/v3/__http://11.2.2.1__;!!FaxH778!NWq_JPeF_TW_mTYtDzy_S2N8jxI9r0OE1EB74sNHTlmago5FNurCBHQyTsCdZZIpKAKDha4$ . JUST my opinion, but likely worth more than you're paying for it... Steve Leyton, President Protection Design and Consulting T | 619.255.8964 x 102 | https://urldefense.com/v3/__http://www.protectiondesign.com__;!!FaxH778!NWq_JPeF_TW_mTYtDzy_S2N8jxI9r0OE1EB74sNHTlmago5FNurCBHQyTsCdZZIpttBHefE$ 2851 Camino Del Rio South | Suite 210 | San Diego, CA 92108 Fire Protection System Design | Consulting | Planning | Training -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Ron Greenman via Sprinklerforum Sent: Monday, August 02, 2021 1:59 PM To: [email protected] Cc: Ron Greenman <[email protected]> Subject: Re: Flexible hose head connectors on a pipe schedule system Tyson, While I tend to agree with you and can think of many pipe scheduling rules going back half a century or more that would suggest that flex heads are ad were outside of the scope of a pipe scheduled system I'm curious as to what criteria you're basing your opinion on. At face value, it would seem that they would be fine as long as no more than two were attached to one-inch pipe in light and ordinary hazard situations, or only one per length of one-inch pipe in extra hazard (extra hazard pope schedule systems having been allowable in times past). On Mon, Aug 2, 2021 at 11:32 AM Tyson Sutherland via Sprinklerforum < [email protected]> wrote: > Sean, > > Because the friction loss of most flex hose assemblies are equivalent > to > 20-30 feet of 1" schedule 40 pipe, in my opinion hydraulic > calculations would be required. > > > TYSON SUTHERLAND, CET > NICET Level III Design Technician > Ohio ASSD #8495 > > 2900 Newpark Drive > Barberton, OH 44203 > > 888-857-2817 x317 > 330-600-0697 Cell > [email protected] > > -----Original Message----- > From: Sprinklerforum <[email protected]> > On Behalf Of Sean Lockyer via Sprinklerforum > Sent: Monday, August 2, 2021 2:08 PM > To: [email protected] > Cc: Sean Lockyer <[email protected]> > Subject: Flexible hose head connectors on a pipe schedule system > > > BE ADVISED - This email originated outside EMCOR. > > > Can flexible hose head connectors (I.E. - "Flexheads") be used on a > pipe scheduled system ? Since calculations were not performed due to > it being a scheduled system, the friction loss would be superfluous, > correct ? Any help would be greatly appreciated. > > Thanks > Sean Lockyer > AIT Life Safety > > > > > > > > > > > > > > > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > > https://urldefense.com/v3/__http://lists.firesprinkler.org/listinfo.cg > i/sprinklerforum-firesprinkler.org__;!!FaxH778!IbjdgPzNvfRo_9I3w-4Lvk3 > gveGdIerQzFD2VZCAmlHnz67IR63DiQoMZo-O_grDDQEnLDg$ > > This message is for the named person's use only. It may contain > confidential, proprietary or legally privileged information. No > confidentiality or privilege is waived or lost by any mistransmission. > If you receive this message in error, please immediately delete it > and all copies of it from your system, destroy any hard copies of it > and notify the sender. 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