×
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

BASE MATERIAL FOR A P1-P1 PQR

BASE MATERIAL FOR A P1-P1 PQR

BASE MATERIAL FOR A P1-P1 PQR

(OP)
Dear all,
We subcontracted the fabrication of a 2in thick pressure vessel (in SA 516 Gr70 N). To back-up the WPS´s the fabricator is showing us a PQR which was done using SA36 as base material, whose tensile strength is 58ksi (minimun).
Surprisingly the two tensile tests broke just above 70ksi which seems to be fine.
My questions are:
a)Is it reasonable that a SA36 base material has a much higer tensile strenght than specified (as it didn´t break @70ksi)?
b)Does the code requiere that PQR qualifications must be done in base material of same mech. properties as the one to be used in production or just to have the same P number?
Thanks in advance

RE: BASE MATERIAL FOR A P1-P1 PQR

# 2

The same P Number is usually the only requierement unless supplementary essential variables are required. In that case the group number is also an essential variable.

However that does not mean you throw out good engineering practice.

Have a nice day.

Gerald Austin
Iuka, Mississippi
http://www.weldinginspectionsvcs.com

RE: BASE MATERIAL FOR A P1-P1 PQR

It is certainly common for A36 to be above its 58ksi minimum.  Most certs I have on hand are between 65-70ksi UTS, but they are well below the 80 ksi maximum.  So there is a good sized range for the tensile of the steel to fall into, but this should be taken into account be people who design with this material.  

I also agree with Mr. Austin, and have also heard it from a member of the ASME B&PV Section IX code committee member that as long as it is the same P#, it is permissable to qualify to weld a base metal with a weld that did not even meet the tensile strength of that metal as long as it met the tensile strength of the metal it was tested with.  I do not know anyone recommending this approach though.  However it is not uncommon to have lower specified strength metals meet the tensile strength of higher specified strength metals, and haven't ever heard of anyone that has an issue with that.

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