"Non-Critical" Welds

Date 02-12-2019 13:53

This may be more of an engineering question but I'd like CWI input.
In this case I am the CWI and also the engineer.

Custom products are being fabricated to D1.1. A handful of prequalified and qualified WPS's are typically used to weld everything.

But occasionally someone (usually not the correct person) will make a decision to make a weld without a WPS (sometimes using a process that is very rarely used and that no WPS's exist for at all), because someone determined that the particular weld joint (usually a fillet weld) is "not critical" to the design; I.E. if the fillet weld were to break, it will not affect the safety of the structure.

Often times these welds in question are attachments to primary load-carrying members. A crack in one of these members would absolutely be detrimental. I don't think I'm qualified to assess the risk of a crack occurring as the result of this welding without a WPS. As the engineer I normally ensure that ALL the welding is designed and specified in accordance with the appropriate welding code but I'm facing argument here.

What is your take on this?

By Lawrence (*****)

Date 02-12-2019 16:18 Edited 02-12-2019 16:25

My take is that it should not happen.

My opinion is that your quality manual ought to state that it "shall not happen."

You are the engineer. Are you ready to put your career on the line and seal the job ?

Things like those happy little architectural details made out of thin gage, attaching to supporting structural elements that maybe are best welded with short circuiting transfer, can be addressed by AWS D1.3 or D1.6 if they are stainless or some other governing specification that is usually easily qualified.   Or just sub that out to somebody who has that stuff in the can.

If you are fabricating them you are responsible for everything.   If the contract documents or your quality manual state that your product is made in compliance with D1.1 and that is not happening? Something, someday, will go wrong.....   You will be hung from the highest yard arm.

There is really nothing wrong with an "Engineering Variance"   So long as you know what your sealing is the right thing to do.   It happens all the time,,, The code is exceeded, or an engineer determines there is a practice outside the scope of the code that is better suited for the project....

An engineering variance is not saying: "Ok lads, just weld it up and get it on the truck" It's providing specific guidance for a task that is not covered well enough for some valid engineering reason.

But you are saying you are not comfortable making risk assessment.... So there is your answer.

By SWN1158 (***)

Date 02-12-2019 17:24 Edited 02-12-2019 17:35

D1.1, 1.1 Scope states that “conformance with all provisions of the code shall be required”, but it also allows for the modification or the exemption of these provisions. 1.4.1 Responsibilities states “the engineer may add to, delete from, or otherwise modify, the requirements of this code to meet the particular requirements of a specific structure.” You have to take into consideration the potential for failure. You said "I'm facing argument here." You may be facing an argument, but is it a valid argument that''s supported by code criteria? As Lawrence said, “Are you ready to put your career on the line and seal the job ?

By Matt F

Date 02-12-2019 22:47

Thanks for the responses - much appreciated.
You've given me better clarity on the topic and I was able to make some progress toward resolving these issues today!