I think ASME VIII Appendix L contains information on how to perform the calculations required by the code. I am not sure if an obround example is shown.
Good Luck.. Richard Schram
Mechanical Integrity Specialist
Pharmacia Global Supply Arecibo-P. Rico
rschram@pharmacia.com
Thanks apiguy, but Appendix L doesn't cover obround openings. I know how to calculate reinforcement of openings, but I really need to know the differences between a circular nozzle and an obround opening. What calculations are different in calculating the reinforcement for an obround opening.
Just check the reinforcement in all planes through the center of the opening as required by UG-37(b).
In practcice this would make only one check on the major axis for spherical heads and two for cylinders, or only one if the major axis of the opening is parallel to cylinder axis (what you shouldn't do by the way). prex
motori@xcalcsREMOVE.com
I think PVELITE software has an option for these openings. I think obround opening is sort of a elliptical opening typically the one for the feed nozzle for crude columns.
See chapter 6 of "Theory & Design of Modern Pressure Vessels" by Harvey, for discussion & formulas for stresses in shell for both circular & elliptical openings in vessel shells & heads, as well as section on Theory of Reinforced Openings.
