Westinghouse Bettis crack-acceptance welding code

Cited twice as the only welding code Tom knows of that permits leaving small cracks in place, on the basis of detailed fracture mechanics analysis. Used as the exception that proves the rule "all codes say grind out cracks."

Except for this one code from Westinghouse Bettis, I don't know of any welding code that says if you find a crack you can leave it, okay. All codes say if you find a crack you've got to grind it out. Sometimes you can grind it out to a certain depth and you don't even have to repair it — just grind out the crack, get rid of the thing. A lot of times on a plate or a piece of sheet metal you stop-drill the hole. You just drill a little round hole at the tip of the crack to get rid of the stress concentration at the head of the crack. That's a temporary fix that's been used for a hundred years. Doesn't always work, but it can stop fatigue cracks.