Non-destructive testing of butt joints of pipes gas pipelines

In welded joints of gas pipelines pipes butt welded with the help of high frequencycurrent, one of the most dangerous defects are cracks including through cracks.The article discusses an optimal complex of methods for crack detection in joints of pipes operational gas pipelines butt welded to the edges of the heating by high-frequency current (HFC).
Materials and methods
Low-carbon steel pipes were tested by methods of visual measurement, ultrasonic,radiographic, eddy-current and magnetic particle.
Results
Tests have shown that for diagnosing welded joints of gas pipelines pipes butt welded in order to detect internal cracks and cracks, onto the object's surface (Fig. 1, 2) are the most effective ultrasonic inspection methods in combination with visual measurement and magnetic particle.
Сonclusions
1. Reliable cracks detection in the butt-weldedto the edges of the heating by HFC is achieved by using complex of nondestructive testing methods. 2. It is recommended optimal complex of methods and verification arrangements of welded joints of gas pipelines pipes are checking a gas content of pit by a gas analyzer, a polishing of welded joint and then proceed to a visual measurement, magnetic particle and ultrasonic testing.