To improve the durability and life of a flange by preventing bending stress from being generated in bolts after the flange is assembled.
The inner peripheral side and the outer peripheral side of one side flange 12 of a flange provided at the connection part 1 of a piping or a pressure container to which internal pressure is applied, respectively have ring-shaped pressure bearing parts 13, 14 which are to be in contact with the other flange 11. For these pressure bearing parts 13, 14, the pressure bearing part 14 on the outer peripheral side is formed not to contact the other flange 11 when the pressure bearing part 13 on the inner peripheral side contacts the other flange 11. In the elastic flange structure in which the outer peripheral side is deflected to generate a larger bearing pressure than that on the pressure bearing part 14 on the outer peripheral side, on the pressure bearing part 13 on the inner peripheral side when the flanges 11, 12 are clamped together by a bolt 2, a bolt 2 bearing surface 3 of the other flange 11 is made to be sloped so that the bearing surface 3 is in parallel with the contact surface 5 of one side flange 12 when the flanges 11, 12 are clamped together.
WARASHINA SHOGO
KITAMURA AKIRA
