Heat Treatment Requirements-ASME B31.3 and ASME B31.1

[Quality2479]

In one of the Project Alloy steel Piping, most of the Piping Spools are in accordance with ASME B31.3 and only one Spool they need as per ASME B31.1. Now The concern is PWHT as per ASME B31.3 for P4 (A335 P11), P5A (A335 P22) Heat treatment soaking time is Minimum 2hours, wheares as per ASME B31.1 for P4 and P5A material the Hold time is Minimum 1 hour/Inch, 15min.

We have submitted WPS as per ASME B31.3 as the 95% of the Project is with this Piping. whether for ASME B31.1 we have to submit separate WPS with 1Hour Soaking time
as per ASME Sec.IX PWHT Temperature and Time is Supplementary Essential Variable QW 402.7.

The Question is whether I have to qualify a separate PQR with 1Hour Soaking time or else we can prepare new WPS with 1hour soaking time by keeping the same PQR qualified with 2Hours.

Thanks for your reply.

 

[XL83NL]

As youve probably already discovered, different codes serve different applications /industries (process piping vs power piping), hence different requirements (sometimes even for the same materials and thicknesses).

What youll have to do is check whether the PQR/WPS for B31.3 work covers the same range as you require for the B31.1 piping. Review the essential variabels in sect IX, and check whether B31.1 adds additional requirements with respect welding on top of that.

I dont have a straight answer, and dont have the code books in front of me, so I cant tell you straight up. However, having, reviewing and understanding the code books is an essential part of an engineers job, so I suggest you review the respective paragraphs of B31.1 and BPV sect IX.

 

[jwhit]

Since you are dealing with minimum times, 2hrs vs 1hr, and your 2 hr procedure more than covers the 80% requirement, I don't see why you can't heat treat everything for 2 hrs without re-writing or re-qualifying a procedure. As I recall, the reason for this clause is a drop off in impact values during long or accumulated PWHT cycles. Your current procedure, if it is properly qualified, covers the situation and possibly more time. I don't have B31.1 or 31.3 in front of me, but don't recall anything that would prevent you from taking that course.

 

[DekDee]

Quality2479,
You have two options
Option 1 is as jwhit noted - just cook it for 2 hours (no change needed on PQR or WPS)
Option 2 - rewrite the WPS and soak for 1 hour only,
Regards,
DD

 

[Quality2479]

Thanks for all replies.

@jwhit
Sir, As per ASME B31.1 Table 132 the temperatures and time not mentioned as minimum. But for alloy steel pipes I think its better to go with 2hours soak time. Please let me know if you have any comments.

Thanks again

 

[jwhit]

Quality,
Para. 132.1 identifies Table 132 as being minimum PWHT requirements so there is no problem, in my mind, extending out to 2 hrs. Where they post ranges, then ranges supersede minimums. I prefer to use a longer than minimum holding time, simply because there are heat treaters who try to take a wham, bam thank you ma'am approach to holding times, that is, get it in, get it out. It increases my comfort zone with how the end product turns out.
I'm guessing that you are fairly new to the codes. Prepare to be constantly confuzzled as you wend your way through it and try to understand them. I have had to do it on my own and it hasn't been easy, and I still have a lot to learn. Good luck.