Abstract: The pipe-coupling comprises a socket member adapted to receive a nipple for connecting a compressed air hose to a fixed supply conduit, for example. The nipple can be inserted manually without any additional actuation of the socket member, since locking is effected by spring-loaded locking members which engage in a circumferential groove in the nipple. When the nipple is fully engaged, a valve arranged in the socket member is open, counter to the pressure of a spring. Release of the coupling is effected by two sliding movements, in opposite directions, of a sliding sleeve enclosing the socket member, the first sliding movement releasing the spring-loaded locking members and the second sliding movement releasing further locking members.