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!

*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.

Jobs

API 6A Secondary Stresses

API 6A Secondary Stresses

(OP)
API 6A section 4.3.3.6 for non standard materials limits the hydro membrane, stress intensity at working pressure, and primary + secondary stress limits as follows:

ST = min[(5/6) x Sy, (2/3) x Rm]
Sm = min [(2/3) x Sy, (1/2) x Rm]
Ss = min [2xSy, Rm]

My question is can the primary + secondary stresses for the hydro-test case scenario be taken as St x 3.0 as in ASME VIII, Div 2?

Surely the hydro-test case would not be limited to the above Ss for design working pressure, right?

Thank you in advance for your help.

RE: API 6A Secondary Stresses

Please note that according to VIII-2, there is NO LIMIT on the secondary membrane-plus-bending stresses for the test condition.

WHY?

Well, the secondary stress limits are to manage a failure mode called Ratcheting. However, ratcheting requires repetition for the loading. A hydrostatic test only occurs once. So, no possibility of ratcheting.

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


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close