Is the 10mm specified by ASME for reinforcement-free use the nominal thickness or the calculated thickness?
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According to ASME’s provisions regarding the elimination of reinforcement needs, the maximum hole diameter for which no reinforcement is required is as follows: when the minimum required thickness of the component is 10 mm or less, the hole diameter can be 89 mm; whereas when the minimum required thickness is above 10 mm, the hole diameter is limited to 60 mm. That is, for components with a greater thickness, the diameter of the openings that do not require reinforcement is smaller. If I need a certain thickness, that is, if the calculated thickness tc is 8 mm and the nominal thickness tn is chosen to be 12 mm, then which range, OD60 or OD89, corresponds to the area that does not require reinforcement?
The calculated minimum required thickness is not the nominal thickness. Look at the English meaning.
That is, for components with a greater thickness, the diameter of the openings that do not require reinforcement is smaller. To answer this question: It only shows that, for the same diameter, the smaller the thickness, the lower the design conditions (pressure, temperature), so a smaller thickness is required ； The greater the required thickness, the more stringent the design conditions are, requiring thicker plates; as a result, the openings that do not require reinforcement become smaller.
For components with greater thickness, the diameter of the openings that do not require reinforcement is smaller