To check the minimum clearance between adjacent flanges when creating a fitting library for flange fittings, assign FLANGE_OD as the dimension name or as a fitting part parameter for the outer diameter of the flange. You must assign this dimension name or part parameter even when you use the fitting of type coupling as a joint fitting, even though it is not a flange. If the FLANGE_OD dimension is not found in a joint fitting, the FLANGE_OD fitting part parameter is checked. In case you have not assigned both the FLANGE_OD dimension as well as the FLANGE_OD fitting part parameter, the outer diameter of the pipe is used for minimum clearance checking.