Abstract: A rubber seal includes a bush (10) of natural rubber and end cups (12) each incorporating a multiplicity of synthetic fabric layers. The end cups (12) are rubberized and are fully integrally moulded into the main portion of the bush so that the final hollow cylindrical member has plane end faces and a smooth cylindrical peripheral surface a part of which is defined by an outer one of the layers of fabric.

Abstract: A method of testing for leaks in tubing and tube joints comprises placing within the tube to be tested a tool having spaced seals so that the seals are arranged on opposite sides of the joint to be tested in engagement at a constant pressure against the internal surface of the tubing. A search fluid such as 1 to 2% helium in air is passed through the tool under pressure and then out from the tool into the annular space between the outside surface of the tool and the inside surface of the tubing between the two seals. The presence of any helium is detected by means of a helium detector for example a mass spectrometer which has a probe extending to a gas trap surrounding the joint to be tested.