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ASME code on-line?

ASME code on-line?

ASME code on-line?

(OP)
Where could I find the following ASME code sections, or especially a summary (or simplified version) of their main or most common stress analysis requirements, on-line? Pressure vessels (Sects. 8 and 9), piping systems, (Sect. B31), Vacuum piping (Sect. B31.9). (Correct me if I'm wrong on the last digit of the vacuum section.) The most important of the above three for my purpose are Sects. B31 and B31.9. A large pipe under vacuum, made by welding cylindrical shell A36 steel plates (two half cylinders with longitudinal seams on each side), failed (collapsed) where the pipe takes a 90-degree turn. The 90-deg turn is made by welding a 0-deg, then 45-deg, then 90-deg segment. The 45-deg segment collapsed (imploded) in its midspan; not at its welded end joints. The flow under vacuum inside the pipe is somewhat corrosive (steam).

I want the quickest and dirtiest analysis equations for resizing the wall thicknesses of the new segments (and for analysis of the joint welds) to bring the piping system up to very mimimum ASME code. The pipe poses virtually no danger to humans or the environment (nontoxic content) and only needs to last two more years. When it failed, it simply collapsed, causing no danger or adverse effect except down time. Any advice on mimimum ASME code requirements or where to find them on-line would be greatly appreciated.

RE: ASME code on-line?

(OP)
No problem. I have access to all that for free. If you knew anything about IHS, you'd know IHS doesn't contain ASME BPVC, Section VIII. It contains ASME B31.9-1996, which hardly addresses piping systems and vessels under external pressure. And what's "Global Documents" supposed to refer to?

Can a knowledgeable person point me to relevant, specific code sections needed for analyzing and sizing pipes and circular cylindrical shells under external pressure? Relevant URLs would also be appreciated.

The 90-deg elbow is a three-segment mitered joint; i.e., each of the two butt-welded, mitered joints have miter angle 22.5 deg. The cylindrical shell thinness ratio (r/t) is 71.5. The thinness factor of the 45-deg segment is 1.643, meaning it's in the realm in which inelastic instability governs (which is to say, its ultimate collapse strength would be governed by a combined strength and stability mixed-mode response). External pressure is far more complex, and a completely different ball game, than internal pressure systems, as internal pressure systems tend to be self-stabilizing, far easier to analyze. So any help would be greatly appreciated.

Thanks,
Mammone

RE: ASME code on-line?

Pipeline sizing for Collapse/buckling [initiation & propagation] due to external pressure is well addressed in DnV 96, DnV OS-F101, BS8010 Part 3 and API RP 1111.

There are also SHELL and BOSS papers as well.

SOM/Plates and Shells by Timoshenko could be your best reference.


Narendranath R
narenr@narendranath.itgo.com
http://www.narendranath.itgo.com
Pipeline engineering is made easy with state of the art computer software, visit www.narendranath.itgo.com.

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