Hemispherical heads...but only internal

[ElCidCampeador]

Hi,
I'm checking a pressure vessel acc. to ASME VII Div.1: it is a simple pipe with to forged flat heads welded at the top and at the bottom.

These 2 heads are flat only externally because inside they are rounded like an hemisperical head.

Is it enough to check heads just acc. to UG-32 or do you think it's necessary also acc. to UG-34 (flat heads),e.g. figure b-1/b-2?

Thanks

 

[SnTMan]

ElCidCampeador, sounds like a U-2(g) situation to me, though I doubt applicability of UG-34. Where did you get those things? Why not use pipe caps? Why make it hard?

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[XL83NL]

We have seen such caps on our vessels as well in the past, if I understand your description correctly. Can you a sketch?
I’d say that if UG-32 passes, UG-34 is obsolete. But I’ve never given it a good thought so I’ll grab a beer and watch the other contenders share their thoughts.

 

[ElCidCampeador]

Here is a sketch of the part:

 

[XL83NL]

OK, just as I thought. Yes weve had similar ones, but then more semi-ellips or another shape. Anyway, I still believe that a pass of UG-32 would not require a UG-34 check, because, essentially, your head isnt flat. The focus, I believe, in this issue should be on where the pressure acts. And it primarily doesnt act on the flat side.

 

[ElCidCampeador]

AI agrees with your interpretation, XL83NL. UG-32 is enough.

 

[XL83NL]

Thanks for the feedback ECC. Good luck on the job.