Distortion
Distortion
(OP)
Hy all
Have a slight question on tolerance given on distortion on piping.....Looked on ASME B31.3 no acceptance criteria...
Is distortion a straight reject?please help....
Have a slight question on tolerance given on distortion on piping.....Looked on ASME B31.3 no acceptance criteria...
Is distortion a straight reject?please help....





RE: Distortion
Be more specific and you may get an answer
RE: Distortion
Hope that Helps.......
RE: Distortion
What's the material? Design conditions? Is PWHT applicable?
Again, be more specific or you may end up getting zero service/advice .
RE: Distortion
If you can give us some specifics then you might get a specific answer, but otherwise we can only deal in generalities.
If all else fails, look at the specification and allownaces within raw material, i.e. pipe comes with certain allownaces for straightness, out of roundness etc so use those as the baseline.
There is always a similar debate on cold pulled bends on pipelines which is when is a wrinkle acceptable. Answer - when deviation exceeds 1%.
You might need to come up with some ideas yourself, or look in your piping construcion specification.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Distortion
You must define the distortion observed; e.g., out of round, other.
RE: Distortion
just to elaborate more....I got a normal stainless pipe 6meter lenght.....in between two stainless shoe attachment welded as a support to a beam structure (Fillet Welds)...The pipe distorted and bowed where the shoes are welded...my concern is i havent seen any where in a piping code given the acceptance criteria on distortion...I Have checked on B31.3 as well Hope that clarifies my question....and to the answers given above thank u all picked some good results....
RE: Distortion
RE: Distortion
I can use it for my refference...
Know anywhere i can download (link) or send me a copy if possible..
Regards
RE: Distortion
Several are only 2-4 page or so documents, but they're inexpensive.
RE: Distortion
RE: Distortion
Neither any of the ASME codes, ASTM specs (it was an A312 TP 304 pipe), PFI, PIP or even the EN 13480 (European design code for process piping which, at some points, is less rudimentary and more straightforward than B31.3) not had any criteria for my problem.
I ended up determining my own set of criteria.
From what Ive read, your distortion might not have been documented (afaik) in any standard, or Im misinterpreting your problem.
Good luck. Anyway, PFI ES-3 is a nice standard. Though PFI standards maybe expensive, some of them provide good guidance on all day fabrication aspects (i.e. problems) for piping.
RE: Distortion
RE: Distortion
Thanks in advance....
RE: Distortion
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Distortion
RE: Distortion
However if the design can't be built in reality due to unacceptable distortion, then the design needs to change e.g. to tees instead of weldolets or full encirclement supports rather than half shell ones or thicker pipe.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Distortion
For wonky pipes or fittings, B31.3 tells you first to use pipe materials conforming to standards (A106,A234,etc.), these standards have their own fabricating acceptance criterias. Not complying with these standards will also not comply with the construction code.
PFIs standards are used for fabricated assemblies, you can use them as guides but, if they arent referenced contractually they arent mandatory.
RE: Distortion
Drawing requirements may well dictate allowable dimensional tolerance.