Proper Use of Clevis Hangers


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Old 05-18-07, 08:59 PM
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Proper Use of Clevis Hangers

I am retrofitting/reworking a 40 year old cast iron main drain pipe. The pipe runs in a channel besides two structural cement beams going in the same direction. The pipe is currently held in place by a combination of plumbers tape that has been anchored with expansion bolts in the cement beam and wire that is strapped to pieces of pipe running perpendicular to line and resting on the adjacent beams.

What I am going to do is place segments of 1 5/8 inch square unistrut perpendicular to the main line so each end of the strut is resting on the beam on either side of the main line. I am then going to put clevis clamps on the pipe and with threaded rod attach them to the unistrut.

My question is do I need to put a nut on each side of the clamp and each side of the unistrut connection or can I just put on bolt/washer on the top where it protrudes the unistrut and one on the bottom of the clevis bracket?

I am assuming the weight of the assembly will be more than enough to keep this in place without having to anchor the unistrut to the support beams.

Thanks,
David
 
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Old 05-18-07, 11:39 PM
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You should anchor the unistruts to the support beam. I would also put a nut and washer on the bottom/top of the clevis hangar and also on the bottom/top of where you attach to the unistrut. So that would be 4 washers and 4 nuts per hanged section. Also, if their is moisture in the area...i personally use stainless steel nuts and washers.


If there is a slab above the pipe...then there is an easier way to do this then to use all that unitstrut. Post back if that is the case.
 
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Old 05-18-07, 11:44 PM
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Slab overhead

Thanks for the reply.

THere are prefabricated beams that rest across the the support beams running parrallel to the pipe. There are some area where I could be able to drill into.

What type of anchor would you suggest using? Do they make it in stainless steel as there is moisture in the area.

Thanks,
David
 
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Old 05-19-07, 12:42 AM
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Yeah..you can get the hangars, 3/8" thread, nuts, washers...all of it in stainless steel if that is what you wish to use. I live in Florida..so sometimes im hanging pipes under houses on stilts above the water....in those circumstances that is what i use..all stainless steel. When im putting houses in the ground and backfilling dirt around the pipes i don't worry about the stainless steel as much....except on the washers and nuts...mostly cause i usually have a big box of em laying around from my jobs by the water

Link: http://www.polyplas.com.au/section_e.html

On that link..you can see the 3 types of anchors i use.
1) Drop-in - drill hole about 1" deep, use tool and hammer to drive the anchor in to concrete.

2) (my favorite) the Pipe SPIKE...drill your hole..grab a hammer and just knock it in. Only requires drill and hammer.

3) Vertical Hanger Concrete - u can get these where it is in tapcon form. Only requires drill and hammer. (can also get a nut driver tip for your drill to drill em in after you drill the hole unless you have a socket set around....course drill is faster)


All 3 of these allow, make sure you get the right size for the allthread your using, allow the threaded rod to be screwed into the bottom of them after the anchor is in place with no need for extra washers and nuts.

I buy mine from my plumbing supply shops..but im sure you can probably find someone who sells em if you don't have access to one. May even try home depot..i never looked there for em.

Also, in Florida (based on International Plumbing code) the code is every 4' on PVC pipe for hangars and support. Not sure what your local code states. It used to be based on pipe size here..but not anymore. Its 4' no matter what size pipe..which i think is a good rule anyways.

If you don't have somewhere to anchor it every 4' then you'll just have to make due with what you have or use the unistruts i guess to do that. And when i say every 4'...i mean if your every 4'6" i don't think anyone is going to complain .
 
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Old 05-19-07, 01:08 AM
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Thanks for the reference - are these available in US sizes

Thanks for the information. My application is actually over water so I will need to use stainless steel. The webiste you referenced had metric sizes - do you know if they make it in standard threads. I do have access to industrial and plumbing supply houses so I should be able to find someting that works.

Will 3/8 threaded rod every 4 feet support a 4 inch cast iron main?

All the best,
David
 
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Old 05-19-07, 10:05 AM
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Clevis hangers

3/8 rod is fine for 4in. cast iron pipe. Most codes I work will allow 5ft. between hangers, luck.
 
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Old 05-19-07, 10:35 AM
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Shacko is correct.
You know...when i said 4' i was talking about PVC...forgot this was a cast-iron discussion with all the clevis hanger talk heh.

Yeah..my code also says 5'...if 10' lengths of cast is used then my code allows clevis hangers every 10'. (just giving you an idea, not knowing what your local code states.)
 
 

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