ASME B16.9 Welded vs Semless Cap
ASME B16.9 Welded vs Semless Cap
(OP)
Dears;
As per my humble experience in righting piping spécifications, when a big size is selected to be welded type (not seamless), the fittings (elbow, tees, reducers) shall be also welded type (not seamless).
However the cap to select shall be seamless.
Does some know the reason of this exception: why caps can't be welded type? and why the standard ASME B16.9 doesn't give any indication about this subject.
Best Regards
As per my humble experience in righting piping spécifications, when a big size is selected to be welded type (not seamless), the fittings (elbow, tees, reducers) shall be also welded type (not seamless).
However the cap to select shall be seamless.
Does some know the reason of this exception: why caps can't be welded type? and why the standard ASME B16.9 doesn't give any indication about this subject.
Best Regards





RE: ASME B16.9 Welded vs Semless Cap
RE: ASME B16.9 Welded vs Semless Cap
My pipe specification is as follows:
Pipe 18" to 36": API 5L Grade B SAW
Elbow, Tee, Reducer: ASTM A234 Grade WPB-W Weld ASME B16.9 BW
Cap: ASTM A234 Grade WPB ASME B16.9 BW
My question is: why the cap material is A234 WPB and not A234 WPB-W?
Best Regards.
RE: ASME B16.9 Welded vs Semless Cap
RE: ASME B16.9 Welded vs Semless Cap
RE: ASME B16.9 Welded vs Semless Cap
Then ask yourself the same question again.
I could only think of very huge (maybe 60" and beyond) B16.9 caps being made of two plates welded together and hen formed. But then Again, such specials might be outside the scope of B16.9 and made according other industry practices.
RE: ASME B16.9 Welded vs Semless Cap
RE: ASME B16.9 Welded vs Semless Cap
RE: ASME B16.9 Welded vs Semless Cap
RE: ASME B16.9 Welded vs Semless Cap
According to ASME B16.9, para. 1.3, there is no any objection for longitudinal seam fabricated fittings, moreover, there is no limit for quantity of seams.
My concern is about testing, taking into account that tests mentioned under sections 9 DESIGN PROOF TEST and 10 PRODUCTION TESTS, make no mention to weld quality