Dear Sirs,

I have designed a vessel of inside diameter 16 inches in which I have used a standard cap (MOC – SA 234 WPB) instead of formed dish head.

Does this standard cap needs stress relieving as per UCS-79 as the percentage elongation exceeds 5%.

I mean as this is a standard cap does I need to check its elongation as per UCS-79?

_________________
Makrand Pandurang Sakpal,
Static Equipment Design,
makrands9@gmail.com,
Ph no:- 9967949656.

Caps are hot formed, heat treatment is included in the specification. Verify it is correctly marked, correct shape and thk, and, if you wish, ask fot MTR. That's it. Mind that, for calculation purposes, the cap, shall be considered as for straigh seamless pipe. Read UG-44
Mauro

Gonzaga,

As per B16.9, shape of cap shall be ellipsoidal as given in ASME Code...So its design shall be considered same as ellipsoidal head. Yes pressure temperature rating shall be calculated considering it as straight seamless pipe as described in UG-44.

Also cap of MOC SA234 WPB is made of wrought material...and UCS79 what is referred above is for plate material...check it again...so not applicable

Thanks.

SA 234 WPB is hot formed. It doesn't need stress relieving. You don't need to check extr.fiber elongation-
Mauro