Todd, A fair amount of experience with two-inlet FDCs with a single clapper and a bypass around the check valve. I don't recommend it as the clapper can be unstable and slam shut...talk about water hammer! I like Tom Worley's suggestion. Dwight HavensFire Code Official - retired. On Thursday, March 28, 2024 at 10:55:32 AM EDT, Fpdcdesign <fpdcdes...@gmail.com> wrote: To a certain extent, this is a rhetorical question. We can use the 1st floor hose valve on the standpipe as a flow outlet. I assume with the available water, flowing 250 gpm through a single 2-1/2” hose and Hose Monster is not going to be a problem. But the real problem is that there is not a good way that I know of to predict this. I won’t know until the job is done if there is enough water from the hose outlet to meet the requirement. Then if the system has to be retrofitted, it becomes a big deal and a big expense. How is everyone else handling this? Todd G Williams, PEFire Protection Design/ConsultingStonington, CT860-535-2080 (ofc)860-554-7054 (fax)860-608-4559 (cell)
On Mar 28, 2024 at 9:54 AM, <Jackie Ward> wrote: Or mech-tee the riser and add a hose valve. Thank you, Jackie “JW” Ward 1-405-240-7076 From: Worley, Tom <t...@firefoe.com> Sent: Thursday, March 28, 2024 8:46 AM To: Discussion list on issues relating to automatic fire sprinklers <sprinklerforum@lists.firesprinkler.org> Subject: [Sprinklerforum] Re: BFP Forward flow test design Just make the main drain 2½. A 2” may even suffice depending on how the water supply is. Thomas R. Worley Estimator/Design Manager Fire Foe Corp. 999 Trumbull Ave. Girard, OH 44420 P: 330-759-9834 x112 F: 330-759-8949 E:t...@firefoe.com From: Fpdcdesign <fpdcdes...@gmail.com> Sent: Thursday, March 28, 2024 9:38 AM To: Sprinklerforum <sprinklerforum@lists.firesprinkler.org> Subject: [Sprinklerforum] BFP Forward flow test design I am working on a re-design of a system where I need to include a provision for doing a forward flow test for the backflow preventer (4”). Due to space issues, I would like to do a by-pass around the check valve to the FDC. Is there a problem with this due to the clappers in the FDC? Also, the building is Residential or Light Hazard and the maximum demand flow is around 250 gpm. If I have to add another outlet for the test, would a single 2-1/2” FDC be acceptable? Unfortunately, I am not aware of any way to predict what would be required. Is there any rule of thumb for the design of these things? Todd G Williams, PE Fire Protection Design/Consulting Stonington, CT 860-535-2080 (ofc) 860-554-7054 (fax) 860-608-4559 (cell) _________________________________________________________SprinklerForum mailing list:https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.orgTo unsubscribe send an email to sprinklerforum-le...@lists.firesprinkler.org _________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org To unsubscribe send an email to sprinklerforum-le...@lists.firesprinkler.org
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