Identification and Judgement Typical Non-defect Wave of Weld Ultrasonic Testing in Oil and Gas Transportation Pipeline

In this article,it analyzed the reason caused deformation wave in weld ultrasonic testing for oil and gas transportation pipeline,introduced the mechanism of production and specific identification methods of several typical non-defect waves,such as saddle-shaped back wave,grooving back wave and welding fillet.Meanwhile,it pointed out that in weld ultrasonic testing,it should judge the location of the first and the second wave,and the back wave corresponding to oscillography screen,the back wave,which appeared in non-correspondence location should not be considered,in addition,it should analyze the characterictics of back wave according to weld geometrical shape and surface state.The non-defect wave was identified through searching reflex conditions,which can prevent misjudgment,and improve weld ultrasonic testing quality.