Engineer approval of WPS 2

[LaCount]

AISC 341 requires that the fabricator submit WPS to the engineer for approval. I know very few engineers that are qualified to review and approve a WPS. How do firms deal with this requirement? One option, I guess, is to subcontract this function to a specialist firm. Is that really the intent?

 

[EngineeringEric]

Welding Procedure Specification?

 

[LittleInch]

Yes,

If you are getting these then normally the welding inspector you would get to inspect the welding would review and approve.

If you're not going to do anything with the WPS, then at least make sure the qualification test matches the WPS! and is in date.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[Ron]

LaCount....this is a common deficiency in the world of structural engineering. The engineers know little or nothing about the materials and processes they expect to be used for their designs. In my opinion, it is incumbent upon the engineer to educate himself to at least know when he is getting hosed by the fabricator or even the Certified Welding Inspector/NDT Inspector or similar.

 

[BUGGAR]

Keep a copy of the WPS that was submitted. Show it to a welder working on the project and ask if he's ever seen this before.

 

[LaCount]

Thanks everyone for the input. My question relates to the EOR's responsibilities regarding Weld Procedires Specifications. Ordinarily, AISC 360 (N3.2(9))requires that the WPS be available but not submitted. In seismic design, AISC 341 (I2.3, J2.1)requires that the WPS be submitted to and approved by the EOR. What is the EOR supposed to be checking for? There are too many variables involved for the practicing engineer to be able make a determination. Do most firms employ and outside consultant to do the review?

 

[CELinOttawa]

I absolutely love that answer Buggar!

 

[Ron]

Oooh...Ooooh...Buggar...I know the answer!

LaCount....A Welding Procedure Specification is relatively straightforward. Its variables are contained in the welding code (typically AWS D1.1). There are nuances of course, but with a little reasonable self-education and a visit to a fab shop you will see it unfold.

The WPS is intended to be used. It is not an administrative exercise meant only for filing.

 

[RFreund]

I think most WPSs are pretty straight forward especially if they are prequalified. Basically checking against the code. Really like a cookbook kinda thing. However, at the same time I feel like you are asking a bit much from the practicing engineer. I mean yes there are minimum requirements that must be met per AWS but am I really suppose to know the required amount of preheat for a particular application based on the grade of steel, thickness and type of electrode employed? Furthermore there are cases where you can meet pre-qualified conditions but the selection of variables will not generate an acceptable weld. Of course these are rare cases and I suppose I could look it up... In Tamboli's Handbook of Structural Connection Design he states that is common for the EOR to delegate the approval of WPSs to the inspector. However in cases where unusual applications that utilize materials in ways that deviate significantly from normal practice it is advisable to to retain the services of a welding expert.

EIT

http://www.HowToEngineer.com

 

[Ron]

RFreund....I agree with you with one exception. I think it is entirely necessary for structural engineers to know all they can about the materials and processes they specify. No, you don't have to be a welding engineer; however, you need to have a basic knowledge of welding processes and their limitations. Do you have to know the pre-heat and post-heat temperatures for parts you design? Of course you do! How can you specify it if you don't know it?

In Engineering Liability 101 you learn that you don't reference or specify a standard you haven't read and reasonably understand.....common sense. Further...if you specify a standard, you had better have it in your library!! My specialty is forensics....I see engineers get raked over the coals by attorneys for this kind of stuff....you don't need it. It isn't that difficult to get up to speed on these things.

Remember.....everything you write, draw or think will be second guessed by someone....probably a lawyer. Be prepared.

 

[TLHS]

I'm not sure exactly how this requirement is structured in the states, but for standards where the proper implementation is the responsibility of the contractor, I'll generally verify that anything that could be considered an input for selection is correct. So in the case of welding, it would be the base material, type of service, weld sizes its applicable to, material thicknesses, etc.

I'll eyeball the rest of it to make sure there aren't glaring issues, but otherwise it should be good to go.

I mean, generally it's either straight out of the prequalified welds, or it's been tested and qualified. Either way, it's pretty straightforward.

 

[BUGGAR]

I had the welder ask me what a WPS was. I told him it meant Whoops and everytime you found a defect in your weld, you were supposed to yell out, "Whoops!" and the inspector would come around and check out the weld for you.

I left the site quickly thereafter.

 

[glass99]

I currently have a project where the fabricator completed the welding without a WPS being in place, let alone submitted or approved. The project is in this crisis mode now because the weld inspector rejected the whole project's worth of steel. The other issue is that no inspector was present during operations, which is an LA County special inspection problem. They are "architectural components" not primary structure, so its arguable that special inspection requirements don't exist.

I am in a tricky position because the welds are 99% probably fine for their intended purpose (this fabricator is generally very good), but the paper is a mess, and as a designer I rely on paperwork. What's worse, a messed up project with liquidated damages, or the liability of not having paperwork?

 

[RFreund]

@Ron - fair enough, you're probably right, no, you are right... But there is only so much time in the day, how am I suppose to learn all this, setup my 175 wind load cases, get work done, I gotta get in some eng-tips time in, eat, sleep, ay dios mio.


EIT

http://www.HowToEngineer.com

 

[BUGGAR]

Ya gotta love the rivet. Read the book "Tracks" by Robyn Davidson.

 

[glass99]

Perhaps structural engineers' weld specs should be performance based, not prescriptive. Either provide reactions at the end of members and delegate design responsibility to a connections specialist, or make the simple strength requirement per inch of each weld type, and have no input on how it is achieved. A desk bound calculation expert (i.e. a typical structural engineer) is always going to be confused about the contents of a WPS.

 

[XR250]

As Ron has implied, the average structural engineer will potentially get his ass handed to him in court. Fortunately, we are only required to practice at a level similar to other engineers in our local area. I doubt any of those know the WPS either.