The end of a pipe (1) is provided with a sealing surface (3). A fitting (5) surrounds the pipe and presses the sealing surface onto a connecting surface of a connecting element. A separate pressing element (13) is provided between the fitting and the end element of the pipe. The fitting is a screw fitting. The coefficient of friction of the contact between the sealing surface and the connecting surface is greater than that of the contact between the pressing element and the end element, and is greater than that of the contact between the fitting and the pressing element.
