Abstract text

A female coupling member having a valve member which provides a secure closing effect is provided. The coupling member includes an outer annular sealing member (56) which is sandwiched between an outer peripheral surface (54) of the valve member and an outer valve seat portion (38) for sealing therebetween when a valve member (44) is at a closed position, and an inner annular sealing member (60) fixedly attached to the valve member (44) on the radially outer side with respect to an inner valve seat portion (42). The inner annular sealing member extends radially inward beyond an annular surface defining a valve opening (40) of the inner valve seat portion. When the outer annular sealing member (56) is sandwiched between the outer peripheral surface of the valve member and the outer valve seat portion, the inner annular sealing member engages with the inner valve seat portion (42) and is elastically deformed so as to be bent, thereby being pressed against the inner valve seat portion (42) for sealing between the inner valve seat portion (42) and an inner peripheral surface of the valve member (44).