ASME VIII vs B31.3
ASME VIII vs B31.3
(OP)
Hi guys,
I'm new here and have a very general question concerning standards;
If I am designing a piece of equipment, what are the factors that would differentiate between B31.3 & ASME VIII.
The equipment is not technically 'holding' pressure but has fluid passing through it (you might compare it to an in line heat exchanger as it is simply a chunk of plates & pipes inserted into a larger pipe. - However ideally I would like to use weldolets and end caps for the connections and would like to know what I can get away with without straying into ASME VIII territory (e.g. is it dependant on fittings or purely if it holds pressure).
Thanks in advance for any feedback.
I'm new here and have a very general question concerning standards;
If I am designing a piece of equipment, what are the factors that would differentiate between B31.3 & ASME VIII.
The equipment is not technically 'holding' pressure but has fluid passing through it (you might compare it to an in line heat exchanger as it is simply a chunk of plates & pipes inserted into a larger pipe. - However ideally I would like to use weldolets and end caps for the connections and would like to know what I can get away with without straying into ASME VIII territory (e.g. is it dependant on fittings or purely if it holds pressure).
Thanks in advance for any feedback.





RE: ASME VIII vs B31.3
There are a host of ways to 'bend' these definitions, but you'd have to have good reasons to bend them very far. With regards to a heat exchanger, I've seen people go either way for say a jacketed/double pipe, but I don't think I've ever seen a shell/tube exchanger called piping (and I'd have some strong opinions if someone tried).
Cheers,
Marty
RE: ASME VIII vs B31.3
But if it's atmospheric pressure, with no jurisdictional requirements, then using a code isn't mandatory. Just use good engineering judgement.
RE: ASME VIII vs B31.3
The components from which a chunk of equipment is not relevant in the sense of assigning a code. [I was going to use the word "determining" but there is so much gray area out there that I figure "assigning" is more appropriate.] I can very easily build a Section VIII Div. 1 scope pressure vessel out of NPS 10 pipe, a couple of end caps, and a few weldolets.
jt
RE: ASME VIII vs B31.3
RE: ASME VIII vs B31.3
You're comments have all been helpful,
Cheers!
RE: ASME VIII vs B31.3
If it is capable of generating pressure, then something- a wire, a steam line etc., has to cross the pressure boundary.
RE: ASME VIII vs B31.3
I believe it is possible to design it to 31.3 but I am still unsure of the exact restrictions. I think I'm going to need to talk to an authority to bottom out the design.
Thank you for your help though!
RE: ASME VIII vs B31.3
This is a big issue we have at my facility. We are forced to use ASME BP&V, and B31 Codes, even when they are not applicable.... yet we force the applicability of the code to pressure systems that are not within the intended scope - because the pressure's are within the scope of the ASME Code.
Use a vehicle tire as an example: It's I.D. is larger than 6" and the internal pressure will be greater than 15 psig... does that make ASME Section VIII, Div 1 applicable? It sure does, but does it mean that we have to use ASME Section VIII, Div 1 to design the tire? No. However - does my contract require me to design tires in accordance with ASME Section VIII, Div 1?? Yes.
(This is an analogy - we're really not making U stamped tires).
RE: ASME VIII vs B31.3
Whenever I design a tire I invoke U-1(c)(2)(c), i.e. a tire is an integral part of rotating equipment.
(said in jest, I have no knowledge of tire industry)
Marty
RE: ASME VIII vs B31.3
Clearly, the tires are transporting compressed air from one location to another. Thus, they fall into the exclusion of U-1(c)(2)(d).