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What distinguishes a pressure vessel from a pipe? 2

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Engineer_M

Mechanical
Nov 15, 2019
20
We have a pipe that's shaped like a vessel. Our supplier is saying its an inline piping component (basically just a bogger pipe). Does any one know what distinguishes a pressure vessel from a pipe?
 
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There are rules in the Code for this.

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P.E. Metallurgy, consulting work welcomed
 
A pipe is just a raw material that is a round hollow cross section. What are you doing with it? How will it be used? If you can answer that, I think you have the answer your question.
 
What country are you in/is this item going to be used? If it’s EU related, the PED has some rules on this.

A sketch and some background info, as pointed out above, would certainty help.


Huub
- You never get what you expect, you only get what you inspect.
 
If the ASME code is applicable, check the Exemptions in Section VIII, Div. 1, which is what I assume Ed is referring to.
 
Basically, a pipe is to transfer the liquid or gas from the point A to B. And, the vessel is to used for a specific function as design by the process, i.e separation, distillation, reaction, etc.
 
“……inline piping component,,”
Please, see the difference between “pipe”, “piping” and “pipeline”

Regards
 
Perhaps the real question is this: when does a piece of pressure piping become a pressure vessel?

Imagine a 16" NPS pipe connecting two pressure vessels. It's bigger than 1.5 cubic feet and relieved above 15 psig, but this line is a piece of pressure piping per a piping code like ASME B31.3.

Imagine that the line is now swaged down to 2" at each end, but still connected to two pressure vessels. Still a pipe.

Imagine now that you delete one or both of the pressure vessels- voila, now it's an ASME VIII vessel.

The codes as far as I've read them, do not teach you this lesson. The first pipe meets all the requirements to fall within the scope of ASME VIII, but it is a minor volume in the system and hence despite this, is still subject to the piping code.

However, without the vessels, it is a vessel in its own right. It is now the major source of stored pressure energy in its own vicinity, and is promoted from being mere pipe to being a pressure vessel It now needs its own nameplate with stamp, its own overpressure protection etc.
 
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