API 1104 appendix b qualification

Date 02-22-2018 22:15

If you figure out how to run water through a branch while the welder fits, tacks, and welds it, please share it with us.

Al

By jarsanb (***)

Date 03-05-2018 15:41

The in-service branch weld does not have a hole cut into the header (See table 1.) The criteria for multiple qualification (welder qual to B-3) requires a butt and branch to section 6.3.2 and an in-service sleeve welded on 12" or greater pipe. No need for an in-service branch, other than a PQR (or coupon test report per section 5) for procedure qualification, for welder qualification unless meeting criteria for single qualification. If performing a single qual for performance, no hole in header for branch connection. My references are to the 20th edition....21st is irrelevant currently.

By flyanbrian Date 03-08-2018 15:22

Ok good to know. so it seems they only need to do the sleeve weld to qualify for in service welding?

By flyanbrian Date 03-08-2018 16:27

so actually we need to do the branch as well because we need to do a WPQ and qualify our welder as well. looking at the branch welds, we only weld on tees and no-blo fittings to tap for blocking lines so I'm wondering if our procedure qualification can just be one of those fittings welded on and tested, any idea?

By jarsanb (***)

Date 03-12-2018 20:09

If you read the 1st paragraph of B-3 I believe it allows exactly what you propose. It's a little ambiguous. Basically, whatever diameter you qualify the welders on, they would be qualified for that diameter and smaller diameters - assuming you aren't putting on a 12" no-blo...if they even make them. Joint design would be limited as well. It doesn't specifically point that issue out but it does cross reference the requirements of section 6.

By flyanbrian Date 05-08-2018 12:14

We will have to do a procedure qualification as well, so will do a branch weld to qualify. What I am curious on now is that I have talked to several welders that are telling me you cannot completely weld up the branch or split sleeve with a 7018 electrode. They are saying the longitudinal weld on the sleeve and root of the branch would need to be done with a 6010 then finished out with a 7018. Does anyone else have this written up for an in service procedure?

By jarsanb (***)

Date 05-11-2018 15:48

You can weld the seams with E7018, if supported by PQR and written procedure. You just arent required to if utilizing backing strips in which case you could use normal cellulosic construction procedures. If the welds do not contact the carrier pipe then they are not considered in-service. For example: if you are installing type A sleeves where only the seems are welded, or a compression sleeve, then no in-service procedure is required assuming reinforcing bars or backing strips are used.

But to your last question, I disagree with your welders. The federal regulators, API committee members, EWI and people from PRCI all have guidance material on this issue. This is not asme, rules and ideals about backing are different than what some seem to assume. If your procdure was qualified with E6010 open root then you would have to run a 6010 root. But if you are attempting to qualifying a procedure with a cellulosic root then fill/cap with E7018 - good luck. Even if you get acceptable results repeating those results on your product line is a pipe dream (so to speak). Industry standard is lohy root/fill/cap. We qualifiy welders with a low hy open root on Butt/Branches and then sleeves pretty much weekly. I would check out the hot-tap forum board on EWI's website. This issue has been hashed out in detail. The post includes many of the top engineers who wrote appendix B and work for EWI, DNV, API and so on....

Now, is the requirement practical? That's a different question. What I can say is that after the welders put in the time to be proficient and qualify with low hy on open root passes (and fill/cap) the skill set transfers easily to our field welds where it's pretty much impossible to have an open root situation with product flowing other than on various branch style taps. which require E7016-H4 root passes for our system.

By flyanbrian Date 05-14-2018 11:35

That makes sense for the butt weld around the split sleeve. We are writing a strictly low hydrogen procedure for any in service welding. As I said this is just for service tees and any blocking fittings we install. I should mention all of our system is 12" or smaller. so for the split sleeve qualification we want E7018 all the way out. I have looked at several other companies procedures and it really varies, only one company has a 7018 all the way out most others are 6010 root then 7018, but that is not strictly an low hydrogen process. We are looking at test qualifications later on in the week.

By jarsanb (***)

Date 05-15-2018 15:59

I can confirm we use low hy for every pass for in-service welding - root pass included. We have 25,000 miles of distribution piping and over 2000 miles of transmission.

side note, what our analysis has shown is that small micro cracks can form immediately after the E6010 root before the lowhy passes have a chance temper the hardness down, which it does, over cracks. So pretty pointless to just cross your fingers. Every field situation presents different risks. Good luck