Abstract: A coupling comprising a tubular inner member (9) defining a socket dimensioned to receive a pipe to be connected to the coupling. The inner member (9) is positioned within a tubular body (1) to define a closed annular chamber, and an inlet (2) is provided tough the body so as to communicate with the chamber. In use, pressurised fluid such as a setting resin is introduced through the inlet (2) into the chamber. The pressure of the introduced fluid is sufficient to cause the radially inwards deformation of the tubular inner member (9) so as to grip the pipe (13, 14) which is received within the socket. Pressure may be applied up to a predetermined limit, or until seal failure.