Originally Posted By: Zircon
Dick, in addition to standard codes (how large of an indication is rejectable), there is the issue of standards to set up the inspection process - especially with UT. The instrumentation needs to be calibrated with a standard that has similar metallurgical characteristics to the barrel being tested. For all practical purposes this means the standard needs to be a damascus, twist, or what have you barrel, equivalent in metallurgical condition (chemistry, thermomechanical processing, and final heat treatment) to the barrel being tested. The standard has reference notches, flat bottomed holes or what have you that the instrumentation must "see" and detect at a specified level. Then, and only then, is the test valid. I believe there are way too many variables to conduct NDE and then make a conclusion as to the safety of any given set of barrels.

As far as proofing goes, it's been around a long while, but it isn't the be-all, end-all either. There are some barrels in the "barrel study" that show definite signs of fatigue failure - something that no single overpressure shooting event will be able to detect.

You are indeed correct.
As I said, I set up, staffed and managed an NDE Department as part of a Quality Control Department. I had Level I, II and III Inspectors for every NDE discipline working for me. I have participated in the NDE of everything from welds on 35" SS piping, Inservice Inspections by underwater UT, radiography and eddy current testing of Steam Generator tubing. I have not listed all the standards because I wanted to keep things simple.-Dick