Threaded rod size needed

Jimbo_5

Hanging 8" schedule 40 black pipe for LPS line, in NYC, and have been told to use clevis hangers with 7/8" threaded rod for support, every 10'   The rod seems like over kill to me.  Any ideas.

icesailor

Threaded Rod, Overkill:

It wouldn't be overkill if it landed on your head and you were killed. It must be in a code somewhere. 3" F&M rings take 1/2" threaded rod.

Jimbo_5

If it were THAT simple, I wouldn't be asking

The PM has a print with no data regarding threaded rod or supports, other than to use clevis hangers w/shoes (no rollers) rather than trapeze hangers.  He is not sure whether or not the hanger spacing should be every  8' or 10'  and he tried, in vain, to order double-expansion shields for the 7/8" rods.  Thus I figured to ask a few questions here in order to find some wisdom.

Alan (California Radiant) Forbes

UPC

Out here, we follow the Uniform Plumbing Code.  For pipe size 6-8", you use 1/2" threaded rod; 10-12" pipe uses 5/8" rod, both spaced every 10'.



Sorry I can't tell you what it is in NYC.

Jimbo_5

Thanks anyway, i

That at least gives me a direction to search in.  For whomever told him to use the 7/8s rod also told him to use double-expansion shields to hold the rods, when it appears double-expansions are only available up to 3/4" thread size.  

archibald tuttle

1 inch double expansion shield

god bless the oil industry.



http://www.apachesales.com/anchor-products/anchor_shield_double_expansion_1.asp



Didn't find 7/8 but I imagine it probably exists.



I've got a good industrial fastener supplier but he won't be at his desk for another hour or so.



Brian

MikeyB

7/8 Rod

In my copy of Plumbers Reference Textbook (4th edition)  by Thomas J.O'Brien, it lists the Suggested Maximum Spacing of Pipe Hangers & Minimum Diameter of Hanger Rod for 8" Cast Iron, Wrought Iron, & Steel Horizontal Screw Pipe, as 19' max span in feet, and 7/8" Minimum Rod size in inches, see attatchment

Jimbo_5

Thanks for the suggestions

Thank you for offering your ideas, I truly appreciate it.  Instead of being the installing fitter, I find myself being part Project Manager, part Engineer, researcher and go-to guy.  We are redoing a steam system in a school, 8" welded pipe, and thus far the shop has no written specs to follow--and I am pulling my remaining hair out trying to get answers for them so I don't become the "fall guy" for following verbal orders that are incorrect.The shop has never done this type of work before, they usually do AC work, so they are leaning on US to advise them what needs to be done.

Brad White

7/8" I agree

Our standard specification has about the same data as your table including maximum spacing.

My $0.02 FWIW

Brad White

No

engineer? I mean, not to shill for the trade, but work in a school, short of an emergency repair, without a P.E. involved seems a bit out of place. CYA is all I can suggest.

Jimbo_5

Thanks, Brad

I agree, which is why I came here with it.  Believe it or not, there is no engineer involved nor even someone competent enough to reach out for one.  The PM has stated that he sent several RFIs but has not gotten any help.  And I do not intend upon being the Fall Guy for offering suggestions in an honest attempt to help him.  I just needed to vent my frustrations to folks that can relate to it.