×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Maximum Thickness Stainless Steel Cryogenic Service

Maximum Thickness Stainless Steel Cryogenic Service

Maximum Thickness Stainless Steel Cryogenic Service

(OP)
Hello,

I'm looking into a note I found from a pipe specification for cryogenic service, design temperature -325F to +150F: For A312 TP304, the maximum permissible thickness is 6 mm. Per my research in ASME B31.3, I cannot confirm this note. Another engineer in my department found literature in B31.3 relating to carbon steel having a maximum thickness of 0.5 inch for the same service type of service. I understand this relates to the brittleness of the steel at -325F, and resume the note for the stainless steel addresses the same issue.

Has anyone else came across this? Or can point to a standard that addresses this?

Thank you for your time

RE: Maximum Thickness Stainless Steel Cryogenic Service

How cryogenic is cryogenic for your service? I can't see CS being used much for liquified gas temperatures.

Piping Design Central

RE: Maximum Thickness Stainless Steel Cryogenic Service

(OP)
Gator,

That's an error on my part. The carbon steel 0.5" thickness is limited by -20f design temperature not the -325F service I described for the stainless. Thanks for catching that

RE: Maximum Thickness Stainless Steel Cryogenic Service

From my cold box days I recall that we used thin as possible stainless so as to minimize mass and therefore cooldown time. Don't know if this is of any further help.

Piping Design Central

RE: Maximum Thickness Stainless Steel Cryogenic Service

And possible thermal stresses due to maximum temperature differentials across the pipe wall.

you must get smarter than the software you're using.

RE: Maximum Thickness Stainless Steel Cryogenic Service

I'm sure what Gator says about limiting the thermal mass of piping in cold boxes is true, but that isn't to say that there's a structural issue with using thick walled SS where it needs to be thick walled in cryogenic service. Cryogenic pump cylinders for example are commonly made with 304 and can have wall thicknesses over 2" thick when operating at high pressure (ie: 10,000+ psi). They have no problem handling high pressure despite the large thermal gradient across the cylinder wall, and there's no restriction in B31.3 or any other code for that matter. There's no reason to limit pipe to 6 mm for cryogenic service and there's no such restriction on piping in the air separation industry.

RE: Maximum Thickness Stainless Steel Cryogenic Service

It always comes down to what type of service and properties are needed. The thicker the wall, the lower the fracture toughness due to constraint, and more likelihood of sensitization due to welding resulting in lower impact/fracture toughness and corrosion resistance. Sensitization is especially a concern with 304 (vs 304L). What will run through these pipes?

RE: Maximum Thickness Stainless Steel Cryogenic Service

(OP)
Gator, BigInch, and iainuts thank you for your feed back. I didn't know about the Cryogenic pump cylinders being so thick. This is good to know.

OGMetEngr, these pipes will see Ethane, Propane, and Butane to name a few; nothing above hydro carbon C5. Like you said, it comes down to the specific application at hand and not using a blanket term.

RE: Maximum Thickness Stainless Steel Cryogenic Service

Any issues are more likely to come with startup and shutdown and their transient thermal stresses across the thick wall. Take that in easy step changes.

you must get smarter than the software you're using.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources