×
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

API 1104 Appendix B question

API 1104 Appendix B question

API 1104 Appendix B question

(OP)
For Procedure Specification, section B.2.1.1.2 it states: For in-service welds, the pipeline operating conditions (pipe contents, flow rate etc) for which the procedure applies should be identified. Conditions may be grouped. Is there an industry standard that is being used for these groupings? Because, in B.2.2.1.2 it states that an increase of the severity of the pipeline operating conditions (in terms of cooling rates) above the group qualified constitutes an essential variable. Pretty vague requirements, to me. Thanks  

RE: API 1104 Appendix B question

The second concern is for hydrogen cracking, since
welds made in-service cool at an accelerated rate as the result
of the flowing contents' ability to remove heat from the pipe
wall.

The flowing contents cause an accelerated rate of cooling the weld.

For hydrogen cracking to occur, three conditions must be
satisfied simultaneously. These conditions are: hydrogen in
the weld, the development of a crack-susceptible weld microstructure,
and tensile stress acting on the weld. To prevent
hydrogen cracking, at least one of the three conditions necessary
for its occurrence must be minimized or eliminated.

When qualifying a procedure,you can group the scenario of various flow rates, contents, although if you go outside of the specified scenario, you must re qualify.
So basically test for the most extreme of conditions. Water has an accelerated cooling rate in the test jig, as opposed to oil.
 

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