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Galvanized standoff hangers are used all the time for CPVC - are they allowed to be used with steel pipe also?
Product data that I'm looking at doesn't say that they cannot be used for steel, but they say "rated for use with CPVC". If they're capable with a weaker product (CPVC), then wouldn't that be more conservative than steel? I haven't come across this before, but we have a unique structure situation where we'll be routing pipe slightly above a structural frame in a lab-type setting, and the standoffs would provide a clean/strong way to support the pipe. Thanks in advance! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe
11 Comments
Dan Wilder
4/11/2022 08:34:58 am
The Tolco Fig 28M (Eaton B3184) is listed for steel pipe up to 2", but the description should state the type of pipe the hanger can support. I wouldn't follow the path of it didn't say I couldn't do it when it comes to data sheets.
Pat Drumm
4/11/2022 08:36:53 am
Before thinking of using them, I would advise you to confirm with the hanger manufacturer that they are listed for steel piping. Without explicit approval on the data sheet for steel piping, I think you're putting yourself in a tough spot. With the steel piping being heavier than CPVC, I don't think you can assume the CPVC listing is comparable with the steel piping.
Glenn Berger
4/11/2022 08:57:58 am
First - Googled "standoff hangers" - Never had heard that term before.
Alex
4/11/2022 09:05:11 am
Hi,
Casey Milhorn
4/11/2022 09:23:01 am
We have used two hole straps for steel pipe, when the weight of the pipe is supported by the member itself. (Steel pipe laying on top of the bottom chord of a wood truss). I'm sure some of our guys have slipped some steel pipe into some standoff hangers as well. Guys in the field get pretty creative at times.... lol, but definitely not designed on purpose that way. I agree with everyone else, but I would add that if the project is large enough and has a structural engineer that is a team player, run it past them, even if you have to throw a few dollars their way (if it makes sense). I would only consider this if it were going to save a lot of $, be completely signed off on by a Structural PE, have approval of AHJ/GC/Design Team, and I just felt like it was the right thing to do in this scenario. There are lots of little things that we use to hang/support sometimes that aren't listed specifically for fire sprinkler piping, but these are more like nuts, bolts, angle iron, etc.... Short answer, probably not worth the risk. 4/11/2022 09:48:20 am
The Anvil Fig.188R (Formally Afcon Fig.514) is listed for CPVC, Steel, and Copper pipe ¾" - 2"
brian walder
4/11/2022 09:58:18 am
*Formerly 😂
Ryan Hinson
4/11/2022 11:00:50 am
I agree with both Dan and Pat. A quick look at an older Tolco 28M cutsheet for these indicates the listing for CPVC piping with maximum hanger spacing less than half what is allowed for steel pipe. The B3184 standoff hanger indicated for steel piping is not UL-listed.
Matthew Foreman
4/11/2022 01:53:41 pm
A word of caution using a galvanized steel product in contact with non-galvanized steel pipe. This dissimilar metal situation causes increased corrosion on the steel pipe. They make all copper stand off material for use with copper pipe for this same reason. The most corroding metal in the fixture becomes sacrificial.
Jay
4/12/2022 03:51:14 pm
You need to reference the data sheet for maximum load the hanger listed to carry, calculate the weight of your water-filled pipe, and then refer to NFPA 13 which requires the hanger assembly to support 5 times the weight of the water-filled pipe plus 250lb. The weight listing is typically for the maximum allowable hanger spacing. In unique situations you can use more hangers (4ft spacing rather than 15ft), therfore less load per hanger, so that each hanger is supporting less weight than ots listed for. Just make sure the structure you're hanging from is able to support additional weight of water-filled pipe also.
Brad
4/13/2022 10:24:19 am
^^^ I like Jay's reply. Also, Pat Drumm was spot on -- the manufacturer is ultimately where the question ought to be directed. At least, that is, if you want an answer that means anything. After getting that answer you'll find out during the submittal if the AHJ is cool with it. Leave a Reply. |
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