Your customer has the responsibility of specifying the requirements of the project. When the project involves more than one standard, the customer should specify when each of the standards apply.
Your customer should also define the materials of construction so you can qualify a WPS to the standard he specifies.
This sounds like a hot potato and the labs are wise to steer clear until all the necessary information is provided.
Have you considered retaining the services of a welding engineer to provide direction to both you and your customer?
Best regards - Al
First of all, let's check if the word "shim" means the same thing for you and me.
Back in my days of erector engineer, "shim" was a strip of variable width (1 to 2 inches), variable thickness (one thousandth of an inch for rotating equipment to maybe half an inch for refinery towers) and variable materials (brass or stainless steel for rotating equipment to plain carbon steel for structural steel) that were put between the equipment concrete foundation and the equipment base to adjust their position (vertical or horizontal), level and plumbness. In the case of rotating equipment they were used also to achieve the required alignment between the driver and driven machine.
If this is so, well, I've never welded the shims to the thicker equipment base, nor never heard that the shims had to be welded. Even more, I worked under the stringent supervision of companies like Sargent and Lundy Consulting Engineers, from Chicago, and The Lummus Company, from New York.
Take into account that after the equipment is plumb and levelled the base is grouted to the concrete foundation, which prevents the shims from moving from their position.
Giovanni S. Crisi
São Paulo - Brazil