Watched a guy chase a pinhole leak for 3 hours at the Shell refinery in Anacortes
Two summers back I was on a turnaround at the Shell refinery up in Anacortes and a pinhole leak on a superheater tube had us all standing around while one guy kept chasing it. He'd bubble test a spot, get nothing, move 6 inches, get nothing, then finally hit it right at a weld seam where the bubbles were so small you had to hold your breath to see them. The lesson wasn't the leak, it was that he wrote down every test spot on his glove with a paint marker so he never double checked the same inch twice. I still do that now, glove or pipe chalk, whatever's handy. Curious if you all mark your test zones or just wing it and hope you remember.