Abstract: There is provided a tensioning device that includes an inflatable pressure vessel, a bellows arrangement, and a valve. The pressure vessel has two superimposed major wall components fabricated from sheet metal and further has an aperture which passes through the two superimposed major wall components. The aperture has an axial direction. The bellows arrangement is connected to and located between the two superimposed major wall components at and around the aperture. The valve is for filling the pressure vessel with liquid under pressure to cause the pressure vessel to be inflated in the axial direction of the aperture.

Abstract: This invention relates to a device [10,42,45,47] for tensioning elongated elements such as metal rods [52], rope [59] and the lik e and comprises an inflatable pressure vessel having two superimposed major wall components [12,14] which include an aperture [28] which passes through them and a valve [20] for filling the vessel with liquid under pressure to cause the vessel to be inflated in the axial direction of the aperture [28].