WPS for repair welds

By Lawrence (*****)

Date 08-23-2013 14:38 Edited 08-23-2013 14:55

Typically it seems logical that if the production WPS was obeyed (including any pre/post heat treatments) a repair would be reasonable.

But your basemetal isn't all that typical... It really sounds like an engineering level decision to include or exclude repairs, and put it in writing on the WPS.

Edit:
You did not mention a code standard, but your reference to a WPS implies that you may need to be compliant with one.

AWS D1.1 (8.2.3) provides some supporting doccumentation as to who exactly is responsible for such determinations

Hope that helps

By welderbrent (*****)

Date 08-23-2013 16:17

There are many personal experiments but not any formal research and conclusions that I am familiar with. A similar discussion is on one of the groups on Linked In currently.

But, your application will always dictate the answer to that question. Materials, loads, cyclic vs static, environmental conditions, and so much more come into play.

That is why the engineer, or, AN engineer, must be involved and determine the risk, liability, success factors to determine if it is safe and prudent to repair or if replacement is more appropriate.

But, while on this, look at D1.1 Clause 5.26 in it's entirety.

Then, more than likely the D14 codes are more suited to your application and I don't have those with me to reference. You may even find you have Marine codes that are applicable.

Do your research to make sure where you stand code wise and definitely get an engineer involved.

Have a Great Day, Brent

By Boon

Date 08-23-2013 16:47

When we say weld repair procedure, what exactly can we expect to find inside such a document? All in descriptive words, sketches or similar contents as in a WPS?
Came across such a request for "weld repair procedure' from client when working on new fabrications.

One scenario I have in mind is : Fillet welding a stiffener angle to duct surface with SMAW process. Asssume A36 / A36 materials. Should the weld be defective, can we repair the weld using GTAW process instead? Is this considered as what need to be stated in "weld repair procedure"? Or the repair should be covered with a WPS detailing the SMAW / GTAW processes?

Regards
Boon

By 803056

Date 08-23-2013 17:59 Edited 08-23-2013 18:05

Hello Boon;

I am not sure if you are making a comment or asking a question.

I categorize repairs as either a repair to a weld that is in-process or a repair that is after the welding is completed and the item placed into service. Even with that, there are specific circumstances that fall outside the "norm" and require special consideration.

I finish a repair procedure yesterday for a client that involves a cast steel component that is essentially irreplaceable. A replacement, if made from the original detailed drawings would cost upward of $200 K with several months of lead time. The repair procedure consisted of a WPS that included considerably more detail than a typical WPS used for a typical fabrication job. The procedure consisted of 5 pages that included a cut from the detailed drawing of the component showing the location of the crack and several sketches of the groove details, special backing requirements, placement of the weld beads, and post weld heat treatment. I would not categorize this as a typical repair that would be encountered during a structural fabrication job.

When developing a WPS for a typical project, I do include "typical" repairs for discontinuities typically encountered during fabrication. Discontinuities classified as defects that would be corrected as part of the fabrication process include things like undercut, overlap, incomplete joint penetration, etc. Depending on the needs of the client a determination is made whether to include the standard repairs as part of the WPS or to address them as a separate item.

There are repairs that a welder can make as they are discovered, there are repairs that need to be reviewed by QC and authorized by engineering, and there are repairs that takes months of planning before the plan is executed. I don't believe there is a "simple" answer to your question.

Best regards - Al

By ssbn727 (*****)

Date 08-23-2013 21:22

To Boon

As long as your welding processes & electrical parameters as essential variables are within tolerances of the original WPS essential variables, and all other essential variables stay the same then there's no need in certain circumstances to write up an entirely new and separate WPS ...But, like Al has already mentioned it depends on the category of repair he has previously posted... And if I were in your shoes, just to CYA or rather to CMA, I would run it by the engineer because there could be some factor(s) where the engineer may become skeptical about going ahead and making the repair(s) without considering a factor or two which may not be so obvious to either of us and certainly not within our pay grade... :roll:

Like Al & Brent mentioned, the first poster's query is not a typical welding repair scenario simply because of the type of alloy being used that will not keep the same metallurgical properties desired for the designed structure if performed by using a typical repair method... So if a repair is applied that isn't carefully thought out by considering all of the possible ramifications which could occur... And if there's no control of the heat input, possible heat treatment required and other factors that must be taken into account in order to achieve a successful repair that meets and possibly exceeds everyone's satisfaction... Then an invitation to failure could be the end result... And if failure is unacceptable which should be everybody's mantra, and yet is permitted then the ripple effects could be catastrophic in many ways IMHO. :eek:

In other words, I was taught by some of the best supervisors and general foreman in the business @ EB that: "All repairs are not to be treated lightly because the long term effects could mean either the boat doesn't get to the wet dock on schedule which would make the company lose a whole bunch of money to possibly killing someone or everyone in our case... So son! Failure is not an option! Carry on!" They also taught me this: "Son, if you're not sure come look for one of us so we can run it by engineering and see what they want us to do, and this is how you must consider any job that you may have a question about how to perform the work or the repair... Basic GM :lol:

P lolol!

Respectfully,
Henry