Safety and economics of ASME 2:1 semi elliptical heads

摘要

THe ASME Boiler & Pressure Vessel Code provides methods for establishing the required thickness of 2:1 semi elliptical heads. Section VIII, Division 1 and Division 2 give formulas to calculate the required thickness based on an allowable stress for internal pressure. Division 2 of that code has a second criteria based on buckling behavior. The buckling criteria governs the required thickness of most 2:1 semi elliptical heads for relatively low internal pressures using Division 2 rules. In these cases the required head thickness is often thicker than the attached shell or even thicker than the same head if designed using Division 1 rules.