If the attachment is square or rectangular instead of a nozzle, enter Cxp, the full length of the square or rectangular reinforcing pad in the longitudinal direction of the vessel. At the junction of the attachment with the vessel, the pad is converted to an equivalent round pad with the following outside radius:
ro = Sqrt(Cxp * Cyp)
This value is only used when PD5500 Annex G is selected on the Vessel tab.