Several type of joints using just one WPS 1

[trolex]

Hi everyone,

I have some doubts that I would like to receive some help.

We've imported an oil-water separator tank which is constructed based on UL 58 (double wall tank for underground installation)for our customer. I requested our supplier to provide all quality documentation for our customer to approve.

I have some problems with WPS (As per AWS) I've got. I just received one WPS which is valid for a B-U2a-45 joint (Single V groove weld with backing. 45° for groove angle). However, the more I see the tank details the more suspects I have that our supplier owes me at least another WPS (or probably more than just one).

I want to know if with just one single WPS (the one with a B-U2a-45 joint) is enough to cover other variations of groove joints just as single bevel groove (T-Joint - TC-U4c-GF) or the same joint but with another groove angle (60° for example). Also, does this WPS cover Fillet joints as well?

Or maybe for every type of joint, I will require one particular WPS?

Please have into account that the welding process is FCAW and Welder is just qualified 1G by WPQR

I appreciate any kind of help.

 

[DVWE]

I am assuming you are referring to AWS D1.1 structural welding code, section 3, prequalified weld joints. I am also assuming the use of prequalified weld joints to AWS D1.1 is acceptable for standard UL 58 (I do not know if this is acceptable or not).

I want to know if with just one single WPS (the one with a B-U2a-45 joint) is enough to cover other variations of groove joints just as single bevel groove (T-Joint - TC-U4c-GF)

No it is not. A separate prequalified WPS for TC-U4c-GF is required.

or the same joint but with another groove angle (60° for example)

The prequalified joint must meet the tolerances listed.

Also, does this WPS cover Fillet joints as well?

No it does not. A separate prequalified WPS is required for fillet welds.

The devil is in the details; she also wears prada.

 

[DekDee]

trolex,
DVWE has given you all the technical answers (and I agree 100%).
You need to look at it from a different perspective if you are serious about ensuring quality.
WPS's are not made just to keep clients happy, they are made to assist the welder in producing quality welds.
If the welder performed all of the welds using 1 x WPS are you confident they are all code compliant ?
There are not many projects that all welds can be in the flat position and on a tank even less so - but, that is not to say it hasn't occurred.
Minimum you should be requesting is additional WPS's as noted by DVWE, a copy of the welder qualification and any NDT reports supplied,
Cheers,
Shane

 

[DVWE]

WPS's are not made just to keep clients happy, they are made to assist the welder in producing quality welds.

That is the understatement of the century. I wish the rest of the world would come to realize this point. Well said, DekDee.

The devil is in the details; she also wears prada.

 

[gtaw]

The WPS can be written for on specific connection detail such as a V-groove or a fillet weld. The WPS can also be more general in nature and include several grooves, fillets, and plug welds if they are used in production and if the WPS provides sufficient details to the welder. I often refer the welder to a annex that details the specific groove details and fillet details. The WPS references the annex that lists the particulars of the connection details. It keeps the WPS to a reasonable length and the annex provides the additional details the welder needs to properly fit the joint.

With a little luck and discipline on the part of the contractor, the detailers, inspectors, and the welders are working with the same documents so that everything meshes.

The bottom line is the welder is bound by what is permitted by the WPS. If the WPS is limited to a V-groove having a 60 degree groove angle, 1/16-inch root opening, and a 1/16-inch root face, that is all the WPS may be used for. The WPS would at least need to be revised to include fillet welds if the drawings specified a fillet weld. A separate WPS may not be needed if the WPS is revised.


Best regards - Al

 

[Maria Garcia]

Nice and great listed here. Thanks

 

[gtaw]

Time for a little personal opinion;

I have worked with clients that have a separate WPS for each weld type and groove type. Their engineering staff, QC, and production were quickly overwhelmed with trying to keep up with the paperwork. The welders, well let's say they tended to put the volumes of WPSs in a corner and rarely bothered to look at them. If the welders are handed too much paperwork it is not going to be used. It’s a fact, I’m sadden to say; welders are not in favor of needless paper.

The welders need direction and they need a system they can refer to when they have a question about the particulars of fit-up, welding parameters, acceptance criteria, and repairs. A streamline system that can provide them with the information they need will be used. That's why I use a basic WPS that tells the welders the particulars of the process used, filler metal required, shielding gas, etc. I use a system of annexes that are referenced by the WPS to address the specifics of the base metal specifications, groove details, fit-up allowances, and acceptance criteria.

Many welders have little knowledge of what base metal specifications are included in each family of P numbers (ASME), M numbers (AWS B2.1), S numbers (NAVSEA), or Groups numbers (AWS D1.1). Pick up a length of pipe and while there is a considerable amount of information printed along the length, however the P number isn’t included. By simply including a reference to the P number and an annex in the WPS, the welder has an additional source of information. The annex lists the P number and all the material specifications (including grades) and product forms included in that P number family. This is also where I list the specific preheat requirements based on material thickness.

Likewise, weld details can be addressed in a similar manner. AWS D1.1 includes somewhere on the order of 120 prequalified groove and fillet details. There is no need to include all the sketches in the WPS if an annex is referenced by the WPS. In conjunction with the annex, the drawing should include the particular groove designation in the tail of the welding symbol. The welder simply looks in the annex to see what the nominal values are for the groove angle, root opening, whether backing is required, etc.

I believe most everyone understands that the acceptance criteria may change from one project to another or from one connection to another. The welders should be informed what criteria is applicable. Again, an integrated system can be used. The particular acceptance criteria can be listed, wait for it……. in the tail of the welding symbol. If one is working to a structural welding code, the welding symbol is a simple vehicle that can be used to specify what connections/joints are subject to the acceptance criteria of a statically loaded or cyclically loaded connection. In the case of ASME pressure piping, a note on the drawing can be used to inform the welder whether the piping is categorized as B31.3 Normal, M, or high pressure. The welder then knows what criteria is applicable to the particular project by looking at the appropriate annex.

Inspectors also need the same information. They shouldn’t have to spend time hunting through the project specifications to see if the information is buried somewhere in that document. It should be included on the drawing. This reminds me of a job several years ago where the project inspector announced he just rejected 90% of the pipe welds. I asked what piping code applied. He responded with, “It’s just pipe.” I asked the project manager, he replied, “It’s just low-pressure pipe.” Even the contractor’s site foreman said, “It’s just pipe.” Talk about a failure to communicate.

The bottom line is an integrated system can be easily instituted to address the needs of the designer, welder, and the inspector. However, a little thought is required on the “front end” to develop a system that can be easily instituted and navigated by those expected to use it.

Granted, a production facility that produces a limited number of products, each requiring a couple of different weld types can get away with a couple of WPSs that are specific to that gizmo they’re building. The problem is more difficult to solve when there many different products being fabricated that involves many weld types where having many separate WPSs can get out of hand very quickly. Each situation should be considered and a system developed that is easy to implement and used. There is no one cookie cutter approach that applies to every situation.


Best regards - Al

 

[Maria Garcia]

Welding Procedures are the guidelines used to perform a weld.Usually welding procedures are developed in accordance with a welding code or standard .