A mechanized flow line for the radiographic TV inspection of welded joints in gas cyliners

Liquefied hydrocarbon gases are stored and transported in cylinders with a diameter of 300 mm and 960 mm long. The cylinders are made of 3-mm-thick carbon steel. To ensure high quality and service reliability of welded joints in the cylinders, longitudinal joints and areas where they intersect circular joints must be inspected by 100% radiographic inspection with penetrating radiation. The welds must be sound, without lack of fusion defects, air holes, cracks, and other defects which impair the soundness and strength of the weld metal. The use of x-ray vidicons for x-ray examination results in a simpler-to-operate, more economic and compact channel for the conversion of x irradiation, gives information in the form of electric signals, and makes it possible to process this information by means of TV technology. The brightness of the image transferred onto the picture tube of the video inspection device can be increased, the size of the image can be magnified, and the transfer of contrast gradients can be improved. Equipment Defektoskop-1, in which x-ray vidicon LI-473 is used as the conversion device, satisfies the requirements on inspection sensitivity (2.5%) and can be used for inspection in dynamic regime. This equipment proved to be most suitablemore » for inspecting the quality of welded joints in the cylinders.« less