Indicating hole on pressure vessel cylinder
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UG-25(e) states that the guide hole should be drilled on the opposite side of the material damage, that is, a hole should be made in the outer wall of the cylinder (with a diameter of at least 80% of the cylinder’s thickness). Have you seen this done before? UG-46 specifies that it should be applied to containers with an inner diameter of no more than 914 mm, with one hole every 0.9 square meters; each container must have at least four holes, which can serve as alternatives to inspection holes (manholes or access holes). Have you seen this type of design before? Let’s discuss this. There’s an opening there, and the wall thickness at that location must be the minimum thickness, which is less than the designed thickness. What should we do?
To supplement what was said above is ASME VIII-1
There is another issue regarding UG-10: it is a material that has not been labeled according to the specifications； b: Marked according to the specifications, but it is material for which no certificate of chemical composition analysis can be provided ； Materials with incomplete C-marking – the above three situations can be considered as materials that meet ASME requirements and can thus be used. Have you encountered any of these three situations? Could you provide some examples?
This indicator hole is a corrosion damage signal hole. This type of structural design is generally used in equipment that is prone to corrosion and where the consequences of damage are severe. When the signal hole begins to leak, it indicates that corrosion has reached the design threshold, which requires immediate attention and appropriate action.
Could some expert advise on how to machine such holes?