For the venting requirement, NFPA 22 section 4.15 will provide some guidance.
Ed K From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org] On Behalf Of John Irwin Sent: Friday, November 02, 2018 7:16 AM To: sprinklerforum@lists.firesprinkler.org Subject: RE: Always something new ... Dry hydrant? Matt, The tanks are 16.5' tall and the outlet is 6" from the base. This is going to result in positive pressure at the pump inlet. What I wonder is if I can get 784 gallons from those (4) 3" outlets. Also, I agree that tanks need venting, but is there direction on how much venting? What standard am I using to design this contraption? Is it 1142 for a dry hydrant? John Irwin Quick Response Fire Protection From: Sprinklerforum <sprinklerforum-boun...@lists.firesprinkler.org <mailto:sprinklerforum-boun...@lists.firesprinkler.org> > On Behalf Of Matt Grise Sent: Friday, November 2, 2018 8:07 AM To: sprinklerforum@lists.firesprinkler.org <mailto:sprinklerforum@lists.firesprinkler.org> Subject: RE: Always something new ... Dry hydrant? It might be a good idea to perform a hydraulic analysis to see how much water can be drawn through those 3" outlets. The pump that the FD is using likely has minimum supply pressure (1/2psi or so). If you need (x) psi at the pump suction flange, and you have (y) psi at the tank discharge (from gravity/water level elevation), then you can flow (z) gpm through the piping network before you lose too much pressure and start cavitating the pump. I would definitely vent the tanks! Matt From: Sprinklerforum <sprinklerforum-boun...@lists.firesprinkler.org <mailto:sprinklerforum-boun...@lists.firesprinkler.org> > On Behalf Of John Irwin Sent: Friday, November 02, 2018 6:43 AM To: sprinklerforum@lists.firesprinkler.org <mailto:sprinklerforum@lists.firesprinkler.org> Subject: Always something new ... Dry hydrant? Ok so here's something new for me . the situation . Client has a client who is using a temporary, tent structure for storage. And right now they are using mobile fracing water containers to supply what I assume would be classified as a dry hydrant. The fire marshal wants something a little more permanent. The property owner is supplying (4) 12,500 gallon water tanks. They appear to each (2) 3" threaded outlets on them. Whether or not these tanks are acceptable per NFPA 22 isn't in my scope. I will make some observations to them but that's about the extent of that. What they are asking of me: Design the manifold system to connect these tanks and feed a 5" Stortz FDC for the fire department to use as a water source in case of fire. It appears that the AHJ is requesting 784GPM for 60 minutes for a total of 47,040 gallons. In which standard do I turn to for the required piping configuration for this and how do prove that I can supply 784 gallons in a minute through these (4) 3" outlets? Other musings . I doubt there are vortex plates in these tanks. What's going to happen? - Is there a venting requirement to keep the fire department from imploding these tanks with their truck? I'm looking forward to hearing your thoughts on this. John Irwin Branch Manager - West Coast Quick Response Fire Protection jir...@quickresponsefl.com <mailto:jir...@quickresponsefl.com> CELL - 727-282-9243
_______________________________________________ Sprinklerforum mailing list Sprinklerforum@lists.firesprinkler.org http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
