How to perform non-destructive testing on the scale of outer containers
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We have just designed a container made of S30408, with a design pressure of -0.1 MPA. According to the classification regulations for pressure vessels, it falls into the category other than those specified in the standards. However, the diameter of the tank is small; there are no access holes for maintenance, and the tank also lacks pipe connections of DN80 or larger. Could you please advise on how to determine the proportion for non-destructive testing as well as the welding joint factor? Thank you
Since your device is relatively small, it is likely to be made of pipes, with the end caps also being formed from whole plates. So the equipment has no Class A welds, only 2 Class B welds. In this case, there is little difference between 100% inspection and 20% inspection; therefore, it is recommended to use a welding joint factor of 1 for 100% inspection.
The original poster should write down all the design conditions before we discuss it! This can only be a guess!
The original poster should write down all the design conditions before we discuss it! This can only be a guess!
Air storage tank, with a diameter of DN1100 and a wall thickness of 8; the medium is air, the material used is S30408, and the volume is 2 cubic meters. The specifications provided by the user specify that no manholes or access holes shall be installed, nor any connections for pressure gauges or safety valves. The inlet and outlet pipes have a diameter of DN65, and there is one drainage port with a G1 1/2 connection. We warned the user about the inspection hole, but the user insisted it wasn’t necessary. That’s why I’m asking everyone on the forum about the issues related to the proportion of non-destructive testing and the welding joint coefficients.
Given the conditions of this tank and the medium, I think a 20% detection rate is sufficient. The material is stainless steel, and the medium does not cause any corrosion; regular inspections are likely not necessary either. If I were to design it, I would choose a 20% inspection.