You are permitted to use the full allowable distance with a flexible sprinkler hose (up to 6 ft without additional support) even when the pressure at the sprinkler is over 100 psi. The reason behind this is the testing that is done to confirm the resistance to upward forces during the listing process.
The reduced armover length for traditional piping without additional hangers is applicable only when two items are in play: pendent sprinkler below a ceiling and pressure over 100 psi. The concern is that the initial upward force of the sprinkler and a longer armover will cause it to move above the ceiling and it may not come back down in the exact same spot. This could mean that the sprinkler would be damaged (e.g. bent deflector) or worst case stuck above the ceiling material. Obviously, this could impact the spray pattern and ability to control the fire. Therefore, the unsupported length is restricted by the standard. Regards, Victoria ***************************************** *Victoria B. Valentine, P.E., FSFPE* [email protected] (240) 813-4373 American Fire Sprinkler Association 1410 East Renner Road, Suite 150 Richardson, TX 75082 On Thu, May 11, 2023 at 12:46 PM Mike Morey <[email protected]> wrote: > If we’re talking “hard pipe” portion of the arm over, we stick with the 2’ > <100 1’ >100 rule for that pipe and where feasible use the longest flex > possible/reasonably priced vs just adding a hung section. > > > > *Mike Morey* > > *CFPS 3229 • NICET S.E.T. 123677* > > *Project Manager* • Fire Protection Group > * Shambaugh & Son, LP **an EMCOR Company* > > 7614 Opportunity Drive • Fort Wayne, IN • 46825 > > *direct *260.487.7824* / cell *260.417.0625* / fax *260.487.7991 > * email *[email protected] > > > > *From:* [email protected] <[email protected]> > *Sent:* Thursday, May 11, 2023 12:41 PM > *To:* [email protected] > *Subject:* [Sprinklerforum] Flex Drops in excess of 100psi > > > > Having an internal discussion, and the thought came up. . , Are there any > discussions or considerations on the reduced arm over length when pressure > is above 100psi? In other words, since the common flex fittings are rated > to 175psi in a bracket, > > ZjQcmQRYFpfptBannerStart > > *Be Careful With This Message * > > The sender's identity could not be verified and someone may be > impersonating the sender. > > ZjQcmQRYFpfptBannerEnd > > Having an internal discussion, and the thought came up.., > > > > Are there any discussions or considerations on the reduced arm over length > when pressure is above 100psi? > > > > In other words, since the common flex fittings are rated to 175psi in a > bracket, attached to a ceiling assembly, can we go to 36” for 1” with more > than 100psi at the sprinkler? > > > > I know as written you cannot. But was wondering if this had been brought > up. > > > > R/ > > Matt > 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. You must not, directly or indirectly, use, disclose, distribute, > print, or copy any part of this message if you are not the intended > recipient. > > _________________________________________________________ > SprinklerForum mailing list: > https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org > To unsubscribe send an email to > [email protected] >
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