D1.6 Stainless PQR Questions

Date 11-05-2010 11:07 Edited 11-05-2010 11:12

Guys,
I have to qualify a CJP stainless steel GTAW procedure on pipe, no backing using gas purge. I am reading through section 4 Qualification and referenceing the joint designations in section 3. A couple of questions I have are;
1) since I am qualifing the procedure on pipe I can use any of the GTAW joints in figure 3.5 right?
for example B-L1b square-groove weld or B-L2b single-v-groove weld.
2) If I use the single V groove weld and I want to change the bevel angle I can. Again because I am qualifying the procedure to make sure it will work.
3) If the footnotes for B-L1b doesnt list letter "e"-gas purge as an option, as long as I qualify the procedure with a purge I am fine.
4) how long should the test coupon be? it looks like 6" (3" and 3") minimum from figure 4.18, that's the only place so far I have need a length.
Thanks Chris

By fschweighardt (***)

Date 11-05-2010 14:32

Is it a tubular structural member, or pressure piping? If pressure piping, would need to be using amse B31.1 and Section IX

By 803056

Date 11-05-2010 17:09

1) since I am qualifying the procedure on pipe I can use any of the GTAW joints in figure 3.5 right? for example B-L1b square-groove weld or B-L2b single-v-groove weld.
a. B-L1b : no, the joint is welded from both sides w/ a back gouge operation. You are proposing a single sided groove weld without backing. The root side purge is not considered backing.
b. B-L2b: a fine choice.
2) If I use the single V groove weld and I want to change the bevel angle I can. Again because I am qualifying the procedure to make sure it will work.
a. Within the limits of the tolerances listed. +/- 5°
3) If the footnotes for B-L1b doesnt list letter "e"-gas purge as an option, as long as I qualify the procedure with a purge I am fine.
a. No problem.
4) how long should the test coupon be? it looks like 6" (3" and 3") minimum from figure 4.18, that's the only place so far I have need a length.
a. Look at figure 4.10. It appears 10 inches is required for the RTS when testing plate. Even when testing pipe, the sample has to be long enough for the machine to properly grip the ends.

Best regads - Al

By eekpod

Date 11-05-2010 19:03

Al, thanks for your reply.

I was looking at Figure 4.12 becasue its for a test specimen for pipe greater than 2", but that figure does not give a length, I see where you referenced Figure 4.10 that shows a length of 10" total.
Would'nt it have been easier if they just put a length in figure 4.12? Rather than have to use the referance of section 4.6.6.1 to tie these both together?
Thanks for the info BTW
Chris

FYI- No these are structural applications, the only thing going through these pipes is purge gas, and air once they are installed, these are not carryone fluid or pressure.

By eekpod

Date 11-05-2010 19:10

The other thing is I see where B-L1b calls for backgouge, but I thought this was only if one were to stay in the "prequalfied" parameters. If one needed or wanted to go outside those variables it would need to be qualified.
Hense that's why I figured if I am qualifying the procedure to stay prequalified it would have to be backgouged, but if I qualifed it with no backgouge and used a gas shielded purge, ran the test and it passed the destructive requirements, then I would be all set.
Isn't that one reason why people need to qualify procedures, sometimes they fall outside the pre-qualifed limitations?
Chris