Abstract: The apparatus, for re-machining safety valves in situ on high pressure/high temperature plant and pipework, comprises a first gearbox and a second gearbox. The first gearbox has a first centre of rotation associated therewith and is configured to receive a driving torque. The second gearbox has a second centre of rotation associated therewith, is coupled to and is configured to be driven by the first gearbox. Coupling means is provided for transferring the drive torque from the first gearbox to the second gearbox. The coupling means is configured to define the location of the second centre of rotation relative to the first centre of rotation. A removable accessory assembly is provided and is coupled to the second gearbox, for carrying out a cutting, grinding or lapping operation to recondition a surface of a safety valve.

Abstract: A contact pressure sensor (10) and method for manufacturing a contact pressure sensor for detecting contact pressure between two surfaces is disclosed. The contact pressure sensor disclosed comprises a substrate (40) for supporting the sensor and a contact pressure sensitive layer (26) sensitive to pressure applied to the contact pressure sensor. The method disclosed also comprises transferring a process post structure (8) that is formed on a first process support substrate (20) from the first process support substrate to a second contact pressure sensor support substrate (40).

Abstract: A joint which comprises a first joint component having an axial aperture and a second joint component having an axial aperture arranged coaxially with the aperture in the first joint component. The joint components have a gasket ring interposed therebetween to act as a fluid seal. The components are joined by bolts and within the gasket ring are a number of stress or strain responsive elements equispaced around the entire periphery of the gasket ring, each comprising a pair of electrodes sandwiching a stress or strain responsive material. The responsive elements have opposed faces which are spaced from the opposed faces of the gasket ring and the electrodes and are connected to an output via leads to give an indication of the stress or strain within each individual element corresponding to the torque force applied to a proximate bolt.