Assuming you have done your homework regarding whether and at what hanger spacing the structure can support the weight of the water-filled pipe in accordance with NFPA 13; in my experience, one still cannot hang from the bottom lip of exposed Z-purlins and must instead hang with something like a Cooper B-Line #51 side beam bracket from the center 1/3 of the purlin spine with ½” nut, bolt, and washers to not void the listing of the support structure itself. From the side beam bracket, a ½” rod hanging down with a nut and Figure B3234 bevel washer oriented such that the rod can hang straight down without lateral loading or bending since it is axially loaded vertically in the direction of gravity thus complying with NFPA 13 (2019) Section 17.2.1.6 along with handbook commentary:
Threaded Sections of Rods. Threaded sections of rods shall not be formed or bent. The requirement in 17.2.1.6 also applies to the rod once it is installed. Cracks can result if the rod is arranged with a lateral load applied to it. In other words, the rod must be axially loaded once it is connected between the building structure and the system pipe. Hanger attachments are available that are listed for attaching to the building structure and that can accommodate angles from vertical, allowing the rod to remain unbent. I have seen many installations whose structural connections do not allow purely axial loading in the rod hangers and induce lateral loads in violation of this standard section. Don’t forget that ultimately, the structural member manufacturer (Butler in this case) must be consulted for allowable connection location means and methods regarding drilling of their engineered structural members. Good luck! Ryan L. Hinson, PE*, SET** \ Burns & McDonnell Senior Fire Protection Engineer O 952-656-3662 \ M 320-250-5404 \ F 952-229-2923 [email protected]<mailto:[email protected]> \ burnsmcd.com<http://www.burnsmcd.com/> 8201 Norman Center Drive, Suite 300 \ Bloomington, MN 55437 *Registered in: LA, MD, MN, PA, TX, & UT **NICET IV - Water-Based Systems Layout From: Sprinklerforum <[email protected]> On Behalf Of James Litvak via Sprinklerforum Sent: Thursday, January 2, 2020 7:37 AM To: [email protected] Cc: James Litvak <[email protected]> Subject: Looking for a 6" hanger for sloped roof I'm trying to hang 6" pipe flat beneath a roof with a 4:12 slope, but having trouble finding an attachment. It's a standard Butler-style building with Z-purlins, and I'm hanging the pipe flat, both perpendicular and parallel to the slope. The Sammy hangers with swivels are not listed, and the slope is way too steep to "adjust" the rod. About the only thing I have been able to find is welded linked eye rods from Tolco (http://www.cooperindustries.com/content/dam/public/bline/Resources/Library/catalogs/pipe_hangers/pipe_hangers_and_supports/TA-EyeRod.pdf<https://nam05.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.cooperindustries.com%2Fcontent%2Fdam%2Fpublic%2Fbline%2FResources%2FLibrary%2Fcatalogs%2Fpipe_hangers%2Fpipe_hangers_and_supports%2FTA-EyeRod.pdf&data=02%7C01%7Crhinson%40burnsmcd.com%7Cbf61c7082e63425ad89308d78f88e034%7Cbfbb9a2b6d994e78b3c795005d555c8b%7C0%7C1%7C637135690352455044&sdata=zAKwLO4H566Pwcw88U0zCtwiFxCqPqgQYZ1%2FPCZcgxA%3D&reserved=0>). However, even though the Z-purlins are heavy gauge, it seems like a bad idea to hang from the bottom lip. In which case, even if I went with the linked eye rods, hanging from the side of the purlin seems like it would create its own difficulty. Does anyone here have a suggestion for how to hang in this situation? I also need to trapeze the pipe across the slope, but I figure whatever solution I can use to hang the pipe across the slope will also work for trapeze hangers.
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