Real Time Radiographic Imaging For Submerged Arc Welded Pipe

According to American Petroleum Institute (API) Standards 5L and 5LX, the longitudinal weld in submerged-arc-welded (SA-welded) pipe may be nondestructively inspected by either radiological or ultrasonic methods. Each method has particular merits for detection of the weld imperfections normally encountered; the ultrasonic method has high sensitivity to planar imperfections, and the radiographic method has high sensitivity to volumetric imperfections. Although both methods have proven capable of meeting customer requirements, recent specifications for pipelines in the Arctic and offshore require automatic ultrasonic inspection.