AWS D1.1 Fabrication Drawing Requirements

[Allen.McGraw]

I'm hoping someone can help me arbitrate a debate between our engineering department and our production managers. Our engineering department wants to produce a "weld standards" drawing that defines weld requirements for the bulk of the configurations our shop personnel will encounter and only provide weld symbols when there is a deviation from the standard. Our production managers are insisting that all weld requirements be indicated on the individual shop drawings. The type of work we do is per-engineered metal buildings (PEMB) and some structural steel fabrication. Who's right in this situation? Any insight you can offer would be greatly appreciated.

Thank,
Allen

 

[DVWE]

Let me ask a few questions for some clarification first:

1. What is your role in the company?

2. What are your thoughts on the matter?

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

 

[Allen.McGraw]

1. I work as a systems specialist, developing the software that each of these departments use, including the design and detailing software. I support all areas of the company and help develop anything from sales documentation to fabrication procedures.

2. Most of the PEMB companies that I've worked with employ a system similar to what the engineer's desire. I don't see any reason why this wouldn't be acceptable. My concern is the language in D1.1 that says the welding requirements "shall" be on the drawings. So, i guess my question is, can a "Welding Standards" chart meet this requirement?

 

[gtaw]

It shouldn't be the welder's or the inspector's responsibility to guess what "standard detail" applies to each joint detail. Each weld should be detailed on the drawing using either a standard welding symbol per AWS A2.4 or if a standard welding symbol doesn't work, a detail showing the dimensions should be included.

It amazes me that some professionals go out of their way to "save" themselves a few minutes of design time, but give little consideration of those down stream that has to become the "designers" because someone up stream didn't do their job.

Years ago I was the fabrication manager in a pressure vessel shop. My welders would spend hours going through their drawings to recalculate dimensions left off the drawings. I presented the Director of Engineering with an "invoice" for the lost production time. I tracked how much production time was lost because the welders had to do what the engineering department should have done for a period of three months. It amounted to over %500,000. I suggested we could lay off most of the engineering department and give my welders raises from the savings due the reduction of head count. It got their attention.

Best regards - Al

 

[DekDee]

I agree 100% with Al.
The more information given to those on the workshop floor the better chance that what you want to achieve quality wise will be attained.
Regards,
Shane

 

[CWEng]

The codes does not tell you how you have to run your operation in this regard. If D1.1 says that the weld requirements have to be on the drawings, it doesn't say how. If your shop drawing refers to another detail, the information is on the drawing, even if you have to look more than 1 place to get it. It's up to you to determine which way is most cost effective for your business. If it is well done, reference drawings can work. If not, you can end up with the scene from GTAW's PV shop.

 

[Allen.McGraw]

CWEng, at the company I work for, this is how its done now and works really well. We have 24x36 charts located in the fab shop. The applicable configurations are minimal, so most of our welders have them memorized. If we have a unique situation, the engineer provides the necessary information. At our sister-company they put weld symbols on all fab drawings. We're trying to normalize process between the two companies and this has been a sticking point.

gtaw, our sister-company's constraint/bottleneck is engineering and drafting, so it's important for us to streamline their design/drafting workflow as much as possible. If their fab shop was the constraint, then I'd be looking at this differently. According to the Theory of Constraints, an improvement anywhere other than at the constraint is an illusion. So, the question becomes, "Is the time/cost saved in design/detailing worth the added time on the back end?" In this case, I think it is. Especially if, like CWEng says, we do it well. When we started doing this (10 years ago) at the company I work for now, there was a minuscule dip in productivity, but because of standardization, it was quickly erased by a productivity increase.

Thanks for the input.

 

[gtaw]

One company I consulted for had sketches of the joint details as the border of each sheet. The sketches included the "As Fit-up" tolerances for the groove angle, root opening, thickness limitations, etc. Their standard practice was to weld everything with FCAW, but the groove details were for SMAW because a footnote in D1.1 says that grooves intended for SMAW can be used with FCAW or GMAW (short circuiting excluded).

The drawings included the basic welding symbol consisting of a reference line, leader, and arrow pointing to the appropriate joint. The groove detail was indicated in the tail of the welding symbol. Each of the groove details around the border were identified, so all the welder had to do is find the correct sketch and all the details needed were readily available.

If the weld detail was not a standard detail, it would be indicated by a complete welding symbol. Of course the standard welding symbol didn't include the tolerances.

The system work fine for full size drawings, but drawings that were in a smaller format made it difficult to read, but that should come as no surprise. Otherwise I would give their system the thumbs up.

Best regards - Al