ASME Section 8 Div 1

[koshyeng]

I need to fabricate a 25" long vessel with 14" Sch 10 pipe to use it a pilot plant for 2 - 4 months. Maximum operating pressure is 10psig.

A elliptical head is welded to one end of the pipe and a flanged connection at the other end.

IS this an ASME vessel or cane exempt from Section 8 Div 1 requirements? This vessel will have chemical mixture with 145 F boiling point.

Appreciate your response.

 

[MJCronin]

In my opinion, the 10 psig maximum operating pressure exempts it from the ASME VIII scope, which is 15 psig and higher.

There is also a minimum volume criteria in ASME VIII ... this may exempt you also

MJCronin
Sr. Process Engineer

 

[SnTMan]

koshyeng, Agreed, your vessel should be exempt. But just to be thorough, you might check with your insurance carrier and / or jurisdiction.

Regards,

Mike

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

 

[Genetix]

10 psig is the maximum operating pressure. How about the design pressure. If design pressure is less than 15 psig then the vessel class is not included in the scope of ASME Sec. VIII, however, U-1(c)(2) specify that any pressure vessel which meets the applicable requirement of ASME Sec VIII may be stamped with the Code Symbol, so I think if your client specify to use ASME Sec VIII Div. 1, you would have to consider all applicable design requirements.

 

[jte]

There is no minimum volume scope criteria in Section VIII Div. 1. I'd be happy to have somebody who wishes to educate me quote me chapter and verse on that.

Operating pressure is irrelevant to Section VIII Div. 1 scope as well. It is the stamped MAWP which matters. This is what Genetix points out above with the slight correction that a MAWP of 15 psi is out of scope. Exceeding 15 psi puts one into scope. Now, a user can very easily decree in their PO that they want a vessel with a stamped MAWP of 14.9 (just to be clear about the exactly equal to 15 psi thing), even if the calculated MAWP exceeds that.

In addition, Genetix correctly points out that merely not being in the scope does not prohibit the design and stamping. Having said that, I personally recommend against U-stamping pressure equipment which is out of scope.