Acoustic testing of welded joints of steam pipelines with the cast stub tube of a slide valve

Specific task has been made, i.e. to determine whether it is possible to conduct reliable inspection of a welded joint in a rolled pipe made of 12Kh1MF steel 18-22 mm thick with a cast branch piece of the lock gate made of 20KhMFL steel 27-40 mm thick, its outer diameter being 290 mm. The lock gate is intended for service under a pressure of 9.8 MPa and temperature of the working fluid 540 deg C. It is shown that acoustic testing of welded joints in the power engineering equipment with cast elements is possible with a sensitivity corresponding to the flat-bottom reflector area of at least 7 mm2, and minimal noise resistance of 2 dB in case of non-optimal angle of the butt end boring on the joint inner surface. Methodological recommendations on acoustic testing of the above-mentioned joints are made