A flange type commonly called flat-face flange has been used in certain classes of bolted flanged connections for many years, yet no Code rules exist to cover this class of flanged connections.This paper analyzes the behavior of gasket and flanges in such a connection and gives design formulas which follow the philosophy of the present Code rules for bolted flanged connections.A numerical example is included which shows the application of the design formulas and compares results obtained with values from strain gage measurements on a pressure vessel of same size.