Limits to Reinforcement Pad

dear pksingle11

greeting to u

you know that according to ASME sec VIII div- I UG-36 that we can not use reinforcement pad up to 3 in in case of the thickness of shell 10 mm or greater than 10 mm. in case of thickness less than 10 mm we can not nse reinforcement pad up to opening 2 in only.

in UG - 37 to UG- 45 the rules to design both of thickness of reinforcement pad and diameter of pad for opening.

as in general we use the same thickness of shell in reinforcement. this thichness in most cases will be safe but you must check it according to ASME calculation. the diameter of pad in mpst case is not larger than the double of diameter of the opening diameter. this thickness and diameter of pad for opening in shell and dished haed only but after u specify the type of opening from UG-36.

in case of opening in flat end and the diameter of opening larger than the half diameter of flat end or larger than short span, the rules in APPENDIX 14 of ASME sec VIII div - I will be used. this rules also will be used in case of design opening in aircooler header (square cut tube headers or header box type).

If nozzles are are near each other, larger diameters of reinforcement pads might interfere with one another. If so, the pads will need to be thicker in order to be smaller.

Other than that, I don't know of a reason to exhaust one limit before the other.