ASME section VIII div-1 & Viv-2

[VPN16]

Currently I am involved in the design of pressure vessel. Thickness of vessel is approximately 5" (SA 516 Gr 70 N), designed for ASME section VIII div-1. If I have to go to fabricator for ASME section VIII - div-2 design, what are the things I have to consider in the design, fabrication, testing, inspection, Code stamp requirements etc. ? - Thank you

 

[GenB]

This is a delicate issue, since the vessel is definitly hi-pressure, spending a few more dlls is not an issue, I suggest you procure a copy of the ASME sev VIII Div II,
latest edition.
ER

 

[VPN16]

Thanks for the reply.

However, what is exact difference between the two i.e Div-1 and div-1. Is there a ready reconer availabe or anyone can help me this ?

 

[jay165]

VPN16:

You need to get a copy of Sec. VIII and read it. There are numerous additional requirements for design, fabrication, testing and allowable materials. If your main reason is to reduce the wall thickness, going to Div. 2 is not going to help much because the allowable S in Div. 1 was raised in '99. For your material (SA 516 70N) your allowable goes from 20,000 psi to 23,000 psi. You would be better off looking at other materials with higher allowable stresses.

 

[codeeng]

The reduction in weight using Div 2 may be of interest to you i.e. cost, shipping/handling restrictions, etc. For Div 2 you'll need to put a User Design Specification together. You'll also need to choose suppliers who are Div 2 certified. Div 2 vessels must be installed at fixed locations for a specific service where operation and maintenance control is retained during the useful life of the vessel (some clients don't like this bit). Otherwise its pretty much the same.