Allowable gap clearance for pipe supports

[steves1080]

I have a 30" diameter pipe that is supported about every 5-6 ft using bolts in a steel pipe support. As you can see in the attached photo, there is a pretty good size gap between the bolt/nut and the top surface of the pipe support, and also between the two faces of the interface. My question is where can I find a good resource on allowable gap spacing between these types of pipe supports (these pipes are galvanized carbon steel and are for transporting water)? My gut tells me to place a shim between the bottom gap and leave the top gap open, but this is purely speculation without some decent documentation on the allowable spacing.

Thanks in advance.

 

[Q_Goest]

Hi steve. Supports every 5 to 6 feet for a 30" pipe seems far to close together. An engineer should have done an analysis on your piping stresses and provided all the information to support the pipe including any gaps to be provided in clamps or other pipe supports. You should have gotten drawings indicating how to support the pipe and where.

Typically, stress analysis is done using a software program similar to structural FEA programs and per ASME or piping code rules, depending on what country you live in. Loads on the pipe due to weight, contents and external loads such as ice or snow are only a small part of the analysis. Thermal contraction/expansion and the resulting stresses can be enormous and have to be taken into consideration when installing pipe this large. I wouldn't look for help on the internet for pipe support analysis, you'll need a piping stress engineer to come up with a proper design for the supports and provide you with engineering drawings.

 

[Travis_King]

Let's assume that OP's company has done some form of analysis, or has decided to forgo analysis and opted to overdesign.

I'm not sure what's going on there in that picture, if the support is floating (not touching the support base nor pulling on the nuts) then it isn't a support, it's just a hanging weight.

If the purpose of some of these intermediate supports is for training (i.e. the support is allowed to move in one direction to allow for expansion) then just leave it. But this is not the standard, nor proper way to train a pipe.

If this is actually a support, shim it and tighten the bolts to their required torques.

 

[steves1080]

Thanks guys.