B31.3 IMPACT Test clarification
B31.3 IMPACT Test clarification
(OP)
I need help clarifying an impact test issue
The background:
The design condition for a pipe is -50 degC
We are using A-671 pipe made using A-516 Gr 60, with mill and impact test certs.
The pipe passes through a bulkhead and also has some additional attachments.
The attachments are just guides and have no effective design loads in themselves. These were spec'd as A-36.
The bulkhead has other loads so it was spec'd as A-516 Gr70 (normalized was NOT spec'd) but the overall bulkhead design was done with a reduction factor of 0.42S. The final thickness is 5/8". From 323.2.2A we find -19 degC with a further reduction (from 323.2.2B) of 42 degC = -61 deg (< -50 degC) so this material does not need impact test.
The welding however, DOES need impact test and the PQR came back with a low value (8 ft.lb in the 516 Gr70 base metal) but good values (about 18 - 22 ft.lb) in the Gr60 and the weld metal.
The questions:
Is the PQR good or do I need to have it requalified?
If so what should we do to avoid having the same problem but not affect the WPS/PQR compatibility?
Can I use the same PQR to support the WPS for the A36 connections?
Did I miss something?
Thanks for your help

david
The background:
The design condition for a pipe is -50 degC
We are using A-671 pipe made using A-516 Gr 60, with mill and impact test certs.
The pipe passes through a bulkhead and also has some additional attachments.
The attachments are just guides and have no effective design loads in themselves. These were spec'd as A-36.
The bulkhead has other loads so it was spec'd as A-516 Gr70 (normalized was NOT spec'd) but the overall bulkhead design was done with a reduction factor of 0.42S. The final thickness is 5/8". From 323.2.2A we find -19 degC with a further reduction (from 323.2.2B) of 42 degC = -61 deg (< -50 degC) so this material does not need impact test.
The welding however, DOES need impact test and the PQR came back with a low value (8 ft.lb in the 516 Gr70 base metal) but good values (about 18 - 22 ft.lb) in the Gr60 and the weld metal.
The questions:
Is the PQR good or do I need to have it requalified?
If so what should we do to avoid having the same problem but not affect the WPS/PQR compatibility?
Can I use the same PQR to support the WPS for the A36 connections?
Did I miss something?
Thanks for your help

david





RE: B31.3 IMPACT Test clarification
The requirements for welded attachments and their welds is really not addressed in ASME B31.3. There are no specific requirements, so it is really a gap. The requirements for attachment materials can be found in 321.1.4 and 321.3.2 and impact testing is not mentioned.
I would think, though, that despite the lack of ASME B31.3 requirements, a good practice would be to have impact tested weld procedures whenever you are welding to a pressure boundary that requires impact testing, whatever it is that you are welding to it. The rules in Section VIII, Div 1, para. UCS-67 provide for this.
You could have avoided the whole issue by qualifying the pipe with Fig 323.2.2B.