Spectral testing of alloy steel valves
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I would like to ask the experts: according to the standards, alloy steel valves require spectral testing, but how can this be done inside the valve body? Does it mean the valve has to be disassembled?
I’m not sure what the original poster means. A spectral test is sufficient for the outer surface, and it must be completed before the assembly testing. All valve components that are under pressure and in contact with fluids need to undergo spectral testing; after the testing, they should be marked to avoid confusion.
Thank you. On the 2nd floor, were you referring to the spectral test before taking the stage? What I’m asking about is the spectral re-inspection test of the valves before installation after they arrive on site.
Reply to 3# whb002002: Check the specifications, SH3501-2002, section 5.3.3, which outlines the requirements for re-inspection of valves
Valve internals such as valve discs, valve stems, and valve seats also require material testing and should be inspected by disassembly.
Arrangements can be made flexibly according to on-site requirements; tests can be conducted using a handheld spectrometer based on the material list provided by the manufacturer. If it is necessary to test internal components such as the valve stem, the valve must be disassembled; after the inspection is completed, it needs to be reassembled and undergo pressure testing to ensure it is fit for use.
Handheld spectral analysis is now widely used; valves with larger diameters can be easily inspected for their internal components, while those with smaller diameters require disassembly.