×
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

Rationale for not specifying maximum soaking time for PWHT

Rationale for not specifying maximum soaking time for PWHT

Rationale for not specifying maximum soaking time for PWHT

(OP)
When there is enough evidence to prove that the notch toughness decreases with extended soaking time, why ASME code does not specify maximum limit on the soaking time for PWHT?

RE: Rationale for not specifying maximum soaking time for PWHT

Quote (ASME Section VIII, Division 1 Foreword)

Accordingly, it is not intended that this Section be used as a design handbook; rather, engineering judgement must be employed in the selection of those sets of Code Rules suitable to any specific service or need
If you have a different take on it, please bring said information forward to the Code Committees so that they may (if there is deemed a need) incorporate such into the rules.

RE: Rationale for not specifying maximum soaking time for PWHT

Because the committee cannot write all encompassing code rules and there are enough cautionary statements to allow one to work around this issue. If you need to qualify material and there is a known notch toughness issue with PWHT you don't use the material if PWHT is required and notch toughness is mandated.


My problem is placing time constraints and what if notch toughness is not important as in Section I?

RE: Rationale for not specifying maximum soaking time for PWHT

Excess of minimum soaking time is waste money.

Regards

rhg

RE: Rationale for not specifying maximum soaking time for PWHT

(OP)
I agree that UCS 56 cannot address post construction PWHT cycles; however it should indicate as a note to complement with Section IX QW407.2. Before taking to code committee, I like to confirm that 80% aggregate time is just an 'uncertainty number' to accommodate the future (or erroneous prolonged soak) PWHT cycles. I understand EN/BS standards have a specified range - is that correct? The actual effect on material properties due to extended hours or number of cycles of soaking varies with the materials of construction. We in the corporate sector put an 'arbitrary' limit of max three PWHT cycles for shop new construction PQR. I'm weary of this 'opinion'.

RE: Rationale for not specifying maximum soaking time for PWHT

(OP)
I guess I need to revise my question here as the QW 407 requirements (80% of the anticipated PWHT cycle time) are focused only for production welds, certainly post construction requirements are not taken into account. 80% or 120%, it is still an arbitrary # which may not truly represent all future repairs even in production shop. Hence my revised question shall be: Can we not expect UCS 56 in Sec VIII to caution the adverse effects of extended soaking time and to remind to meet the Sec IX welding qualification requirements?

RE: Rationale for not specifying maximum soaking time for PWHT

The Code book is not an engineering handbook, and will never be a handbook. Again, expertise is required and the code book provides only minimum requirements. Ultimately, the engineer decides on material selection and joining.

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