higher strength materials for pressure vessels in ASME B31.3
higher strength materials for pressure vessels in ASME B31.3
(OP)
Greetings,
I am designing a small fitting to be installed inline on a 1-1/2" pipe. This fitting is basically a small pressure vessel packed full of components (so that there is very little free internal volume) and is required to be machined out of a solid block of material.
Now, here is my problem. Another engineer has told me that for asme b31.3 or a category H fitting, that there are severe limits on what materials can be used. Apparently only forged billets or plate can be used for pressure holding components, and the maximum allowable stress is 17ksi for any material regardless of actual yeild strength etc.
When I read ASME B31.3 I do not see these limits written anywhere(although they may still be there). It seems to me that I can use any material in table A-1 for my pressure vessel.
Does anyone here have any insight to this problem? It would be helpful to me if I could make my fitting from a higher strength material, but not completely necessary... thanks!
-Kristjan
I am designing a small fitting to be installed inline on a 1-1/2" pipe. This fitting is basically a small pressure vessel packed full of components (so that there is very little free internal volume) and is required to be machined out of a solid block of material.
Now, here is my problem. Another engineer has told me that for asme b31.3 or a category H fitting, that there are severe limits on what materials can be used. Apparently only forged billets or plate can be used for pressure holding components, and the maximum allowable stress is 17ksi for any material regardless of actual yeild strength etc.
When I read ASME B31.3 I do not see these limits written anywhere(although they may still be there). It seems to me that I can use any material in table A-1 for my pressure vessel.
Does anyone here have any insight to this problem? It would be helpful to me if I could make my fitting from a higher strength material, but not completely necessary... thanks!
-Kristjan





RE: higher strength materials for pressure vessels in ASME B31.3
Patricia Lougheed
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RE: higher strength materials for pressure vessels in ASME B31.3
-Kristjan
RE: higher strength materials for pressure vessels in ASME B31.3
RE: higher strength materials for pressure vessels in ASME B31.3
Where abouts are you located? For this application it would be most appropriate to talk directly with your jurisdiction/AI.
For example, here are some newsletter discussions
Ontario:
htt
Alberta (page 4):
http://www.absa.ca/newsletter/2008-v13-iss2.pdf
RE: higher strength materials for pressure vessels in ASME B31.3
http://www
RE: higher strength materials for pressure vessels in ASME B31.3
So to get back to my original question, if hypothetically I use section VIII of the boiler code to design the pressure containing components of my device, are there materials with higher strength than A36 steel that I could use? My reading of section VIII suggests that I can use, say a 4135 steel forging for my pressure containing component and that would give me the relatively high allowable stress of 34.3ksi at room temp...
It might sound like a simple question, but there is another engineer here that is telling me that a36 is as strong as is allowed for pressure containment...
-Kristjan
RE: higher strength materials for pressure vessels in ASME B31.3
From the discription of your part it sounds like could be condsidered a "manufacturers standard" for which you can kind of pick your methods.
Agree, talk to your AI.
Regards,
Mike
RE: higher strength materials for pressure vessels in ASME B31.3