Problems with surface inspection
Thread Content
Fixed tube sheet heat exchanger, with the tube sheet serving as a flange, and stubs on the tube box. The specifications state that surface MT testing is to be carried out on the Class C joints between the equipment flanges and the tube sections; it is certainly intended that surface testing be performed on the Class C joints between the shell flanges and the short sections. People are wondering whether MT testing is required for the Class C joints between the tube sheet and the shell when it is written this way in the drawings
For table probing, the inspection and acceptance section of NB/T47020 requires table probing to be carried out.
That is a Class C joint between the equipment flange and the shell; what is discussed here are the Class C welds between the tube sheet and the shell
It definitely refers to the inspection of Class C joints between the equipment flanges and the shell, as specified in the standards for pressure vessel flanges. The tube sheet serves only as a flange; it is not a device flange. Moreover, the joint between the flange and the shell belongs to the tube side, while the joint between the tube sheet and the shell belongs to the shell side. Whether testing is required depends on the requirements specified for the shell side in the drawings.