Any guide of Piping deflection because of steam tracing.... 2

[Chengin]

Hi, I'm a chemical Engineer work in a refinery.
After a process unit construction, we found out that a pipe line is deflected like above pictures.
What I found through googlings, they say normally maximum piping deflection is 1inch or 1/2 of nominal pipe dia.
I checked my company's specification and it says it shouldn't exceed 20mm.

But I think they are only about piping loads.
Could they be applied to these cases?
Or are there any guides or standards for piping deflections from steam tracing?

 

[bimr]

The structural deflection limits that you posted are used to determine the need for pipe supports. If you have a 20 foot span, 1/2 inch is equal to L/240, a common limit for beam deflection should liquid pooling be an issue. Aesthetics has as much to do with acceptable deflection limits as anything else.

Pipe deflection does not mean much without knowing the application, pipe size, material of construction, temperature, etc.

It appears that the pipe in question was installed without any consideration for thermal expansion.

 

[mk3223]

May have the piping engineer to review the piping thermal expansion design by using the steam tracing temperature, and the stress analysis for the proper pipe guide support along the pipe rack as necessary.

 

[EdStainless]

It might be good to double check the steam controls on that one pipe.
Are you sure that it is not running hotter than it was designed?

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P.E. Metallurgy, Plymouth Tube

 

[GD2]

JJINY,

There is no cookie cut solution for steam trace lines. A formal stress analysis is required. I am sure it was done by the EPC company who designed the piperack. Look up the project documents and find out the EPC company and raise the issue with them. Sometimes, it becomes very tough to contact the right project group as they must have move to other projects after delivering your project. If the project is new, it may still be covered through a performance bond.

If not, there is no short-cut. You have to initiate another brownsfield project for another EPC company to re-stress the lines.

GDD
Canada

 

[KevinNZ]

Has a support that should have been sliding been made fixed? Check all the supports are the type originally designed.

The fixed supports at each end of the pipe will have had very large forces on them. Check for damage to the supports, pipe rack and the pipe itself, including the pipe shoe welds.