Enter the outside diameter of the pad.
The diameter of the pad is entered as the length along the vessel shell (not the projected diameter around the nozzle), although these two values will be equal when the nozzle is at 90 degrees.
A hillside or Y- angle nozzle makes a non-circular hole in the vessel. As a result, a reinforcing pad with same width around the nozzle will have different diameter in the longitudinal and the circumferential planes. For this type of nozzle, enter the smaller diameter, which is:
Pad OD = 2 * pad width + Nozzle OD