Welding of heat exchange tubes to tube sheets
Thread Content
What type of weld is used for welding the heat exchange tubes to the tube sheet? Previously, all processes were classified as Category D, but now some say they should be classified as Category C. I believe that the \"joints where the flange is connected to the shell or nozzles\" specified for Class C welds in GB150 is not applicable to the welds between the heat exchange tubes and the tube sheet. Instead, the tube sheet should be considered part of the shell and thus classified as Category D. How do the other experts understand it?
The joint that connects the flange to the shell or nozzle is not the weld between the heat exchange tube and the tube sheet
A stricter standard should be applied, as there are risks associated with heat exchanger leaks and difficulties in maintenance
The fillet welds between the heat exchange tubes and the tube sheet generally have separate inspection requirements; if it is necessary to classify these weld joints, I believe category C would be a more appropriate classification.
The welds between the heat exchange tubes and the tube sheet are classified as Class C welds
Is it mentioned on what basis it is classified as Category C? !
Class C welds: The most common ones are the welds between flanges and pipes, as well as those between the cylinder shell and the tube sheet; therefore, they are essentially fillet weld joints.
This post was last edited by gn_1984 on 2017-1-3 at 13:28. The standards do not provide specific classifications for this type of weld, but in design and manufacturing, the structure of the weld is generally chosen based on process requirements such as equipment pressure and medium temperature; fillet welds are the most common. The testing requirements also differ. The reason I consider it to be Category C is that I base my judgment on the fact that both the socket weld between the flat-faced fitting and the flange, as well as the weld between the flat-welded flange and the fitting, are corner welds. This is merely an individual’s understanding and perspective.
If it falls under Category C, then according to the new regulations, is magnetic particle testing required after October?
Yes, it mainly depends on how the designer views the design pressures and medium requirements