A pipe coupling is configured such that when a male coupling member and a
female coupling member are to be connected with each other, a valve
disposed in the female coupling member is partly inserted into the male
coupling member so as to come into press-contact with the valve in the
male coupling member, and to cause displacement of the valves, to thereby
open a fluid passage in the pipe coupling. An O-ring is provided on the
interior surface of the male coupling member. A sleeve is arranged in a
female coupling member such that a forward end portion of the sleeve is
inserted into the male coupling member in such a manner that the outer
surface of the forward end portion of the sleeve sealingly engages with
the O-ring, while allowing the valves of the male and female coupling
members abut against each other within the forward end portion of the
sleeve.