Class A and Class B weld joints not governed by tolerance specifications
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As the title suggests, I’m not sure whether this approach is correct. For a shell-and-tube heat exchanger, the pressure in the shell side is 1.0 Mpa; brine flows inside it, and the design temperature is 38 degrees. According to the code on solids and fluids, such equipment should not fall under the scope of these regulations. However, the shell and tube sections have longitudinal and circumferential seams – are these seams classified as Type A or Type B joints? Should the welding procedures and diagrams indicate these seams? Please help clarify this
The shell side can meet the requirements of a pressure vessel, and the longitudinal ring welds on the shell side can also be referred to as A and B welds; however, their requirements are different from those of the A and B welds in a vessel.
(1) The fact that a product falls outside the scope of the Compliance Regulations does not mean that the owner has no technical requirements for it. (2) If the product falls under the category of atmospheric pressure vessels, it shall comply with GB/T 151-2014 \"Heat Exchangers\" and the provisions of the design drawings. (3) The Class A and Class B weld joints in the shell side are the main welds of the product, and the process requirements should be specified in the welding procedure.
This definitely meets the requirements of GB150 and GB151; the welds should be classified in accordance with the standard requirements. The fixed volume gauge does not specify weld categories.
Non-conformity regulation also applies to welding joints of types A and B
Being not governed by acceptance regulations simply means it is not **regulated**; however, the product still needs to be designed in accordance with relevant standards. For products that are under pressure, design should follow GB150 standards, and it is normal for such designs to not be subject to regulation.
For systems under pressure, the specification of 150 is sufficient
Those falling under the jurisdiction of 150 must be designed, manufactured, and inspected in accordance with the requirements of 150