ASME B31.5 Coil manufacturing

[MSchmidt000]

Good day everyone,

Just a quick question.

I've recently been hired to a piping manufacturer in their QA dept, so I'm relatively new to process piping and manufacturing/fabrication. I've familiarized myself with some of ASME B31.3 for components relative to our supply. Although, we're also involved in producing coils for heat transfer units, and that should be included in Heat exchanger code.

My question, what is the requirements for material testing for 3/4" piping used for tight 8" OD coils? Does manipulating the material really affect the pressure rating of the material?

Thanks,
M

 

[gr2vessels]

Yes, the thinning of the pipe external wall on the coil OD will normally exceed the pipe wall tolerance, hence the rating will decrease, I'd say in proportion will the wall thinning percentage. There is no credit for the work hardening. I'm not sure about the de-rating for the pipe ovalization during the coil forming.
cheers,
gr2vessels

 

[MSchmidt000]

Thanks for the reply gr2.

I'll look into it further for the shape of the coil. Perhaps it's only a customer spec. in terms of apperance.