AWS D1.1 98 states in section 2.2.1 that the drawings shall "clearly distinguish between shop and field welds". In our office we never specify whether a weld is a shop or field weld because we regard this as means and methods. Regardless of where a weld is completed, we just want the weld to meet a given quality as defined in AWS and our specifications. Can someone tell me why AWS D1.1 has this requirement.
I am only guessing.
If all welds are called out for a fabricated assembly such as boiler ductork, It would be good for the fabricator and erector to know what welds they are responsible for as opposed to the fabricator deciding which welds would be "better" for the field erctor to make.
Without this being defined, you could have very large pieces to install or excessive joints to make in the field.
Gerald Austin
http://www.weldinginspectionsvcs.com/
A few more comments in addition to the above:
1. Often the fabricator and erector may be 2 separate entities. One performs shop welds, the other field welds, contractually.
2. Field welding often has requirements more stringent than those welded in a shop (qualification, electrode requirements, etc.)
3. Planning for transportation of weldments or structures to the field site are a major consideration without having to permit oversized loads. ($)
4. Post weld testing (shop and field welds may have different requirements).
John, as the owner of a welding business that does both field work and shop welding, I can say that the above answers are correct. It defines who is responsible for what, where and when. Contracturally and financially this is important. It is not normally the case for a job to be started in the shop and finished in the field by the same company. I admit that even though I have the capabilities and the facilities, most of my installation work is manufactured by someone else. Someone along the way must decide who and when is the best time and place to make a weld, you cannot leave this decision to just anyone, too many welds would never be made and I imagine you would hear alot of "it's not my responsibility." I hope this helps.
Respectfully,
Mike Sherman
Shermans Welding
As already mentioned, there are many concerns to be considered with shop and field welding. Everything from quality, to responsibility, to ease of erection. I believe the section 2.2.1 is intended to get the communications going, like it has in this forum question. Not everyone will approach a job in the same way but I can say the most enjoyable projects I've ever worked on were the ones where everyone knew what they were doing, what the others were doing, and how the quality affected each operation.
Granted, many times a designer or engineer may not know what should be a field weld, but the erector and fabricator do and they should discuss them. 2.2.1 doesn't say who must make the decision, but the AISC Code of Standard Practice gives some guidance on who is responsible for drawings.
CHGuilford
Just an FYI Re: the AISC Code of Standard Practice. Although it was revised March 7, 2000, we still find many of the contract documents refering to the previous version (6/10/92).
It appears in some cases that the contract spec book was "cut and pasted" from a previous contract. It can cause some unwanted frustration.
We find the latest version of the Code to be extremely helpful throughout the duration of the contract. We encourage all of our estimators, detailers, project managers and quality assurance to be famaliar with it.