×
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

Comparison ANSI/ASME B31.3 AND B31.8

Comparison ANSI/ASME B31.3 AND B31.8

Comparison ANSI/ASME B31.3 AND B31.8

(OP)
We have new piping materials (including fittings)
all with correct material certificates , WPS and PQR and all according to ASME / ANSI B31.3.
Design pressure under 100 barg , design temperature between Zero and 80 Degr. Celsius

Is it possible to use the obove for a part under ASME/ANSI B31. 8 ( eight !!)

If THE answer is NO , how can we make this possible ? I mean which steps , recirtification , extra calculation, re-qualification, etc,.. have to be done to get a system approved for B1.3 also approved for B31.8

RE: Comparison ANSI/ASME B31.3 AND B31.8

I don't think that there will be a problem as the design factor in 31.3 is lower than B31.8.  However, B31.3 may not address Charpy toughness testing in the same manner as 31.8 (in the sense that 31.8 demands the designer to assess the need for it and a lot of people overlook running ductile fracture in rich gas lines for example).  Personally, I don't subscribe to the B31.3 approach of allowing A106 Gr B to go to -29 deg C without Charpy testing (in line with a lot of upstream oil companies).  In addition, if you have any fittings or pipeline parts that have girth welds, 31.8 demands that they be made in accordance with API 1104 which may not hold with the standard used to manufacture the fittings.

Steve Jones
Petroleum Development Oman LLC
Muscat
Sultanate Of Oman

RE: Comparison ANSI/ASME B31.3 AND B31.8

The big difference is in 31.8 you cannot weld onto the pipe.  In 31.8 you must perform a strenght test and in 31.3 it's only a leak check, the differnce really being the lenght of time required.  I've co-qualified pipe before by doing this.  Do the calcs. interpert the x-rays to the more stringent; poristy , high/lows, excetera are a little different, then test for 4 hours.

Don't get too concerned on temperature since your design is above the lower limits.

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