Circles in tank weld seams, see photo 4

[flatbottom]

I know that this was done as a means to perform destructive testing on the tank shell girth and vertical seams. What was the procedure called and where can I get some information on this old practice? See attachment.

 

[SPDL310]

I believe the procedure you are referring to was known as trepanning. As for information on how the procedure was actually preformed etc the best route would be to speak with an old welder or inspector who actually preformed the procedure. Another route would be to find old versions of welding/ASME codes.

 

[JStephen]

The older AWWA D100 codes I've seen allowed trepanning, but gave zero detail about how to do it.
When in college (about 1980), I remember seeing some plugs that had been cut out of a propane tank weld. They were about 3/4" diameter. Those plugs could have been in existence a good many years, that doesn't imply they were cut in 1980.
I assume magnetic drill + hole saw blade would be in order.
Since I've been in the tank business (since 1985 or so), I've never seen or heard of trepanning actually being done.

 

[Duwe6]

At 1", 25mm and smaller, a handheld drill with a hole saw is fine.

 

[valleytank]

I doubt you will find a procedure. This would have been outlined in the original contract where the contractor would lay out a procedure for examining these girth seams and at how many locations to satisfy the client. There wasn't anything to it back in the day except using a hole saw, cut a cookie out, examine the cross-section and fill it back up.