FLUID COUPLING

PROBLEM TO BE SOLVED: To stabilize pressure loss by keeping a flow path cross-sectional area constant while enhancing development efficiency of a fluid coupling by employing a common shape in a plug, socket and valve in product development of fluid couplings of different types.SOLUTION: In a standardized fluid coupling which includes a valve 32, a valve holder 42 and spring 41 inside a plug 12 and socket 13 having insertion holes 14 and containing a first opening end 16 and a second opening end 17 facing the first opening end 16, respectively, the diameter of an abutting surface 33, the diameter of first opening end 16, the diameter of first opening end side inclined surface 34, the diameters of inner peripheral surfaces of the plug 12 and socket 13, the diameter of maximum diameter part 37, and the diameters of inner peripheral surfaces of the plug 12 and socket 13 are made common. Axial dimensions of the second opening end side inclined surface 38 and axial dimensions of an linear-shaped inner peripheral surfaces of the plug 12 and socket 13 facing the second opening end side inclined surface 38 are changed.