To provide a pipe flange connection structure, which can prevent uneven clamping without the need for torque management, and can perform connection by which sufficient air tightness can be maintained for a long period of time.
At least a pair of protrusions 4 are formed at a connection surface connecting with a flat-plate flange 10 of a flange 1 with a protrusion so as to oppose each other with a flow path hole 2 as a center, the flange 1 with the protrusion and the flat-plate flange 10 are made to possess rigidity capable of avoiding warpage when a bolt 30 is fastened by torque within a specified torque range, a differential height between tip faces of the protrusions 4 and a seal face 5 around an opening of the flow path hole 2 of the flange 1 with the protrusion is made to be a height which is adjusted so that the protrusions 4 abut on the flat-plate flange 10 when the bolt 30 is fastened within the specified torque range, the bolt 30 is applied with torque and fastened, and when the torque reaches a value within the specific torque range, the protrusions 4 abut on the flat-plate flange 10.
| JP2004027986 | JOINT STRUCTURE FOR EXHAUST PIPE |
| JP2004125048 | FLANGE COUPLING STRUCTURE |
| JPS60131783U | 1985-09-03 | |||
| JPS5935788U | 1984-03-06 | |||
| JPH11325353A | 1999-11-26 | |||
| JPH0317493U | 1991-02-21 | |||
| JPS6429246U | 1989-02-21 | |||
| JPH0854063A | 1996-02-27 |
| US4787654A | 1988-11-29 |
Kiyoshi Yasushima
Takanashi Norio
Motoki Shandong
Taku Ogawa
Murata Kensei
Moto Otani