What testing can be used as a substitute for the vacuum chamber method test for storage tank bottoms?
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May I ask, if a equipment manufacturer fails to conduct the vacuum chamber test for the tank bottom plate, what testing methods can be used as a substitute? Can magnetic particle testing be used as a substitute?
The vacuum box method is generally used for inspecting the bottom of large tanks, as there are many long welds in that area. In my opinion, using magnetic particle testing improves the inspection process; but isn’t it cumbersome to apply magnetic particle testing to so many welds? If there are many welds at the bottom of the tank, kerosene penetrant testing can be used; if the welds are not long and hassle is not a concern, magnetic particle testing seems to be a viable alternative to the vacuum chamber.
The equipment manufacturer failed to conduct a vacuum test on the bottom plate, which indicates that your tank is not very large. It would be best to specify the diameter and height of the device.
For those with a diameter of 10m or less, can the base plate be changed to permeability testing?
Magnetic particle testing, penetrant testing, and the vacuum chamber method are different types of inspections; the former is a surface non-destructive testing method, while the latter is a leakiness test. The latter cannot be replaced by surface non-destructive testing. Section 12.2.1 of GB50341-2014 contains relevant requirements.
First, you need to know why the vacuum chamber method is used for testing. The vacuum chamber method is used because the storage tank is too large, allowing only on-site assembly and welding; other leak detection methods cannot be applied from the bottom of the pipes, whereas the vacuum chamber method enables inspection of the inner surface for leaks. PT testing is only a surface inspection, not a leak detection, so it cannot be used as a substitute. If your device is not large and the conditions permit, you can use kerosene leak testing for inspection.