Again, the spotlight shines on "Sprinkler Stockholm Syndrome".
There's a fine line between high-level professional service and taking responsibility for the owner's tight grip on the budget. "We know that the problem lies in the capacity of the fire pump, and the client wants to save as much as possible and reduce the risk due to the structural load." So if the pump is the problem, why bang your head against the wall when there are serious potential downstream consequences to anchoring large diameter piping to existing framing? Are you in a seismic zone? If you're near DF, then the applied loads from sway bracing will be equal to or greater than the dead loads from hangers - do you know if the roof will even hold the weight of this two-riser configuration you're asking about? Are you getting paid for multiple iterations of the design and will you liable to revise it if it gets shot down by a structural engineer or the owner's insurance? If I was in your position (and I have been multiple times), my best advice to the owner would be to upsize the fire pump and be done with it. Work backwards from the maximum pipe sizing you're sure you can hang and brace; bring a structural engineer on board right now and have all aspects of the roof framing calc'd for the proposed loads of a spec' system design. If the largest piping doesn't work, revise for a larger theoretical pump and re-calc' until the roof can bear both dead and live loads. Then upsize the pump (as needed) to meet what is likely to be a higher pressure demand. Our firm currently has two ESFR upgrade projects at existing buildings here in Southern California and we are the design team lead. One is three systems and one is nine; both buildings are 1980's vintage, one with wood truss framing and the other with panelized glu-lams and 4x purlins. We have an architect, structural engineer and electrical engineer as subs and all aspects of the projects will be signed off by licensed professionals before they go out to bid. Instead of taking ownership of what might be a festering pile of controversy, put it back on the owner to bring in ALL of the resources that THEY need to save THEMSELVES the money they don't want to spend on a new pump. Has there been a cost analysis of what upsizing the pump will cost? Do you have electrical capacity to drive a bigger motor or is it a diesel? How much will new underground service entries cost compared to a pump upgrade? I'm having a hard time getting my head around how shortsighted this owner is. My Friday rant, DONE. Felicidades, Esteban Steve Leyton, President T | 619.255.8964 x 102 | www.protectiondesign.com 2851 Camino Del Rio South | Suite 210 | San Diego, CA 92108 Fire Protection System Design | Consulting | Planning | Training -----Original Message----- From: Gerzayn Fuentes @ KOLTEK.MX [mailto:[email protected]] Sent: Friday, July 19, 2024 12:59 PM To: [email protected] Cc: Francisco Reveles @ Koltek.mx <[email protected]> Subject: [Sprinklerforum] UUP / Plastics A unexpanded exposed Hello everyone! We are designing an expansion project for an Plastic A Unexpanded Exposed or UUP with racks warehouse. Design specification is 12K25.2 @ 60 psi + 250 gpm x 60 minutes. The existing pump is 2,000 gpm @ 120 psi, and an existing underground schedule 40 steel network is more than 10 years old. We are using a factor C=100. The above gives us 4" branch lines, 8" mains and a 10" riser, using 3 mains and it gives us the curve, but we need to lower the pipe diameters. We have never seen a 10" riser. We know that the problem lies in the capacity of the fire pump, and the client wants to save as much as possible and reduce the risk due to the structural load. Our question is, can we have a grid sprinkler system with 2 risers of 8" that feed it? We can't find anything in NFPA or FM Global standards that prevents this, but at the same time I've never seen a system like this installed. Greetings and we look forward to comments. -- Gerzayn Fuentes Campos / director general [email protected] México. www.koltek.mx -- <https://expofire.ownersys.com/registro> _________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org To unsubscribe send an email to [email protected] _________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org To unsubscribe send an email to [email protected]
