ULTRASONIC PIPE INSPECTION PROVE-UPS CAN BE IMPROVED
B.J. Hodges Lone Star Steel Lone Star, Tex. In extensive tests conducted in its laboratories, Lone Star Steel found conventional manual ultrasonic prove-ups of pipe imperfections to be consistently inaccurate. Error rates ranged from 65% to 100%. On an average, we found that of every five joints of casing rejected by manual prove-ups, four did not have rejectable imperfections.