Torque Values for U-Bolt Pipe Supports

[RiniEIT]

I am looking for standard torque values for U-bolts, used to support pipe, ranging from 1" to 6" pipe. Does anyone have a nice torque table or chart that I could use as reference for this application?

 

[europipe]

You can't use a u-bolt as anchor, it's too weak for that.
Don't think there a torque tables for that.

 

[LittleInch]

I agree, I 've not come across "standard" torque values because there is no standard force to apply and a wide variance on the type of pipe, thickness and whether you're holding it down onto a curved pad or a point load type support.

Something relatively nominal would be my guess - hand tight plus 1/2 turn or 5-10 Nm?

you need to be careful though as U bolts are a difficult thing to simulate as they will resist a certain force, but are not "anchors". Really they shouldn't touch the pipe, but just stop it jumping off the support.

If you've modeled the system as a set of simple supports then U bolts will affect the movement and stresses in your pipe system because if you tighten them up they are not simple supports anymore, but nor are they anchors.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[DSB123]

LI,
Agree mostly with what you say but there are "grip type" and "non grip type" U bolts. The first type I would use to "fix" small bore pipes (up to 1.5") at the likes of utility stations. The second type would be used to "guide" small bore lines to as you say stop them moving around too much. From my point of view U bolts should not be used on pipes larger than 3" nb. I have seen one used as an "anchor" on the end of a 14"nb tailpipe. Luckily the pipe slid through it when the bursting disc blew and the pipe folded back on itself. If it had been capable of resisting the "jet" force it would have lifted the structure and its foundation out of the ground and thrown them as a missile.

 

[RiniEIT]

Hey guys,

Thanks for the feedback. The piping will be supported by a cantilevered steel angle underneath, and the U-bolt will be used to simply hold it in place. It won't be used as a hanger or used in a manner where the U-bolt would take any pipe load. I'm calling out to have the U-bolt fit snug against the pipe and have the U-bolt double-nutted (one nut on each side of the angle that the U-bolt passes through). I was thinking to have the second nut torqued to some standard torque values for a low carbon bolt. I only need adequate torque values to ensure the second nut doesn't come loose over time.

I used torque values for a Gr. 2 steel bolt, which is on the lower end for torque values.

https://www.myodesie.com/wiki/index/returnEntry/id/3036

Good enough or too much?

 

[JGard1985]

Good enough, I think specifying snug tight is acceptable, so long as you aren't in high vibration environment

Grinnell pipe hangers only require nuts to be snug to achieve full rated load (Look at Figure 137SS in Grinell Catalog)

Just make sure you don't pinch the pipe with U-Bolt if you wanted free axial expansion.

Jeff

Jeff
Pipe Stress Analysis Engineer

http://www.xceed-eng.com

 

[MikeHalloran]

I don't know what your corrosion environment is like, but this may be of interest:

A couple of years ago, I worked on a pair of power gen skids for installation on an oil rig, with the expectation that they would last for 30+ years in the Gulf of Mexico. The customer demanded I-Rod Nu_Bolts by name, instead of generic u-bolts and bare angle supports, in order to avoid crevice corrosion.

https://stoprust.com/i-rod-pipe-supports/

Mike Halloran
Pembroke Pines, FL, USA

 

[MickMc]

1 nut on each side of angle will be non-grip therefore acting as guide and you would be torquing against the angle not the pipe and a lock nut would suffice to avoid loosening.

 

[RiniEIT]

Thanks Gents!