1.1 This standard prescribes the method for ultrasonic detection and evaluation of longitudinal and circumferential defects in seamless pipes and tubular products (excluding cast) by direct contact method and by immersion method and shall be applicable to pipes with outer diameter greater than 12 mm and with outer diameter to inner diameter ratio not greater than 2.
1.1.1 For tubes with outer diameter to inner diameter ratio greater than 2, for circumferential scanning the angle becomes less than 30°. Owing to problems connected with critical angle, circumferential scanning is not possible if the entire wall scanning is required. In such cases either partial scanning with angle probes or use of normal probing technique may be resorted to.
IS 6394-1971 history
1972IS 6394-1971 Operating procedures for ultrasonic testing of metal seamless pipes and pipe products