| 摘要 |
PROBLEM TO BE SOLVED: To constantly obtain a fresh fluid in a constitution in which the fluid does not stay in a coupling state. SOLUTION: In a coupling fitting body, a seal packing fit part 15 of circular shape is provided at an inner peripheral surface of its front end. A circular arc surface having a center of curvature at an inside of the seal packing fit part 15 is provided in at least a part of a seal packing 16. The seal packing 16 comprises: a seal packing body 17 arranged to be capable of turning with the center of curvature inside the seal packing fit part 15 as a center; and a seal part 18 integrally formed with the seal packing body 17 and projecting to opposing coupling member 14 from an end of the coupling member 14. When the seal part 18 is elastically in press contact during a process of coupling a pair of coupling members 14, the seal packing body 17 is turned in a direction in which the seal part 18 separates with the center of curvature as its center. When an internal pressure is applied to the seal part 18 in a state of coupling of the pair of coupling member 14, the seal packing body 17 is turned in a direction in which the seal part 18 is in press contact as the center of curvature as its center. |
