Bolted flange connections with full face gaskets have commonly been used for low pressure piping. No stress calculation method is given in J.I.S. and A.S.M.E. codes. The analyses on stresses, bolt loads and gasket loads of this type of flange were made by taking into consideration the gasket properties and the flange bending flexibility. The experiments were performed under gasket seating and pressurized conditions by using integral flanges with a small size hub simulating the weld part in a pipe-flange ring junction. The flanges of 280mm in outer diameter and 20mm in thickness were made of aluminium alloy and steel. Two kinds of PTFE gaskets of 2mm thickness were used for the tests. Calculated results showed a good agreement with the test results. It is clarified that the stress analysis of the flanges with ring type and full face gaskets can be performed on an identical basis.