To provide a seal packing capable of increasing water-tightness to either positive pressure or negative pressure.
A first sealing section 46 is provided to a circular packing body 45 molded by a member having elasticity to press-contact to a fitting groove in a state of water-tightness. A first curved section 53 is extended to an upstream side of waste-water from the first sealing section 46 to curve to a downstream side by return. A second curved section 54 is extended to the downstream side of waste-water from the first curved section 53 to curve to the upstream side by return. A second sealing section 55 is extended to the second curved section 54 to press-contact to the inner circumferential surface of a first diameter widening section. The first curved section 53 and the second curved section 54 are respectively curved to the upstream side and the downstream side of the waste-water to form bending sections 57 and 58. A radial elasticity of the packing body 45 is increased to surely come into press-contact with the first sealing section 46 and the second sealing section 55. Water-tightness can be increased to either the positive pressure or the negative pressure.
Satoshi Kabazawa
Tetsuya Yamada