A pipe coupling is disclosed which comprises a plug (14) and a socket (12). When the plug is inserted into the socket, the plug first urges sleeve actuators (28) radially outward to axially move a sleeve (22) and, thereafter, urges locking elements (20) radially outward to move the sleeve further. Eventually, the locking elements and sleeve actuators are fitted within a locking recess (14-2) of the plug to securely connect the plug and the socket.