2 questions about API 1104

Date 05-08-2003 07:28

1. No limits defined for limit on penetration. The only ref is to burnthrough as defined in clause 9.3.7. But I did have a client whi imposed the limits for excess weld metal or "reinfoircement"as described in clauses 7.8.2/7.9.2
2. Tungsten inclusion is not defined as a defect as per API 1104

By George-kh (**)

Date 05-08-2003 16:16

If there are no limits for tungsten inclusion and excessive penetration according to API 1104, every amateur welder can pass welder qualification and do anything with joints!!!
How is it possible API not to consider these two defects?

By JTMcC

Date 05-09-2003 16:45

Well, I can refer you to a whole lot of pipeline welders that would disagree with that point! By excessive penetration, I assume(!?) you mean a stringer bead that is protruding into the pipe too far? If so that isn't addressed in 1104 that I know of and I've never seen or heard of it being a problem. In my opinion, you can't put that much of a bead in the pipe without burnthrough, which IS adressed by 1104 as mentioned in an earlier answer. It sounds like you need a copy of API 1104.

JTMcC.

By insp76

Date 05-10-2003 18:10

JTMcC, I`ve welded pipline myself ,before I got in to inspection and I have done inspection work on pipeline jobs. When you open your API 1104 Standard you will will see the first paragraph on page 1 states the differtent processes allowed, smaw,saw,gtaw,gmaw and oaw. As you may know with the exception of smaw these processes are very capable of internal reinforcement greater than .125. So API could in fact address this issue, instead of leaving it up to the owner of the equipment to detail a spec not allowing internal rienforcement greater than,say, .125. A large % of the pipeline work is still performed using the old E6010+,E7010,E8010 etc. These rods are fast freezing and will burn through and wash out the landing and the wall before exessive penetration is a factor. Maybe that`s why API has not added this to the accept/reject criteria. As far as the tungsten inclusion issue is conserned ,tungsten allthough it is metal, it is the "wrong metal" and is considered a foriegn object such as sand and many other materials that are not spelled out in API 1104 as a cause for rejection. Tungsten inclusion is often considered a volumetric imperfection and is accepted or rejected accordingly.

By sayeeprasad (*)

Date 05-12-2003 10:01

The API committees for writing 1104 must have had their own reasons for writing the code the way they did. I am not technically competent to argue their reasons, but what I presented were facts as per API 1104 and straightforward replies to simple questions.
However to add to the confusion since we have so many people here who worked on pipelines before, as per DNV OS F101, type of clamp and the time between root and hot passes is an essential variable whereas API 1104 specifies only that these details to be mentioned in the WPS, but they are not essential variables themselves.