There might be enough code commentary for the AHJ to reject this. 29 psi is a lot. Was the pressure gauge bleed out before the test or on the high side of the system?
[cid:[email protected]] Steve Welsh, PE \ Burns & McDonnell Senior Fire Protection Engineer M 410-978-3836 From: Skyler Bilbo <[email protected]> Sent: Wednesday, January 21, 2026 8:13 AM To: Discussion list on issues relating to automatic fire sprinklers <[email protected]> Subject: [Sprinklerforum] Re: Hydrostatic test I would say you meet the requirements of NFPA. As a side note, this is usually due to an increase of temperature during the test, and also means you have a lot of trapped air in the system. I say all of this to say that you need to pay attention during the flow switch test. With a lot of trapped air in the system you may see the flow switch go into the flow position, then reset itself before it overcomes the retard time. If this happens, you will want to try to get as much of that trapped air out as you can, and redo the flow switch test. Thanks, Skyler Bilbo On Wed, Jan 21, 2026, 6:51 AM <[email protected]<mailto:[email protected]>> wrote: Is it acceptable for a hydrostatic test to have a gain in pressure of 29 psi for wet fire sprinkler system? I cannot find exact verbiage in NFPA 13 about gain of pressure. _________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org To unsubscribe send an email to [email protected]<mailto:[email protected]>
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