Abstract: Pipelines are maintained in subterranean location by a plurality of weighting devices which include an elongate central raised region enclosing the pipeline and generally planar flanges extending outwardly from the central raised region in a common plane. Backfill overlaying the flanges provides an increased resistance to upward movement of the buried pipeline under the influence of an encompassing fluid medium or other force.

Abstract: The axial forces imposed on a rotor of a fluid machine such as a compressor is controlled by modulating the pressure supplied to a piston and cylinder device acting between the rotor shaft and housing. A parameter indicative of axial force on the rotor during operation is monitored and changes in the magnitude and direction of the axial forces countered by varying the pressure in the cylinder. The net axial forces imposed on the shaft may thus be controlled in a predetermined range.

Abstract: A displacement transducer suitable for use in a magnetic bearing measures the flux density between a pair of components and divides a signal indicative of the magnetomotive force between the components by the flux density signal to obtain a signal indicative of displacement.

Abstract: A rotary electrical machine comprises a rotor assembly and a stator assembly separated by an air gap. The stator is formed from discrete generally pie-shaped pole pieces having a progressively increasing radial slot to accommodate winding of the coil. The pole pieces are preferably wound from a grain oriented ferromagnetic tape to improve the permeability of the pole and its saturation level. Groups of poles may be separated into sectors. In an alternative embodiment, at least some of the pole pieces are formed from both a permanent magnet and ferromagnetic tape to provide a constant bias between the rotor and stator assemblies.

Abstract: The present invention relates to an apparatus and process for estimating the pour point of a hydrocarbon oil. The pour point of hydrocarbon oil gives an indication of its low temperature properties, and is determined according to the time-consuming procedures set out in the American Society of Testing and Materials (ASTM) test D-97. The present invention generally provides a convenient means to estimate the pour point of a hydrocarbon oil, by directing a flow of pressurized gas towards a sample of the oil, and determining the warmest temperature at which the gas flow does not cause a substantial surface wave on the oil surface.

Abstract: An axial magnetic bearing includes a rotor overlying a coil in a stator. A second coil is disposed at a location where it does not exert a significant force on the rotor. The second coil generates a magnetic field to oppose and substantially cancel the stray magnetic field generated by the first coil.

Abstract: A magnetic bearing has a number of pole pieces disposed about the circumference of the shaft supported by the bearing. To inhibit magnetic flux migration within the bearing, magnetic barriers of non-magnetic material are interposed between pole pieces at selected locations. Magnetic guides prevent magnetic saturation of the bridging portion of the pole pieces prior to the poles' saturating.

Abstract: A gas compressor, particularly of the kind for boosting pressure in gas transmission and petro chemical process, has an impeller mounted on an impeller shaft of the overhung type mounted on front and rear bearings and having at least one impeller mounted between the front bearing and a front end of the shaft. Annular seals are provided co-axial with the shaft which separate an inner space communicating with the shaft front end from the suction end gas space which lies outside the seals. The seals include an outer seal and an inner dry gas seal. Pressurized process gas is supplied between these seals at a pressure higher than suction pressure and is vented from the inner gas space at a pressure well below suction pressure to limit gas pressure forces on the front end of the shaft.

Abstract: A gas compressor, particularly of the kind for boosting pressure in gas transmission lines, has an impeller mounted on a shaft located between two bearings with the gas space surrounding the impeller being separated from the bearings by dry gas seals, including a least primary dry gas seals. The primary dry gas seal adjacent the discharge end of the compressor is of larger diameter than the corresponding seal at the inlet end of the compressor so that pressurized gas acting on the respective rotary parts of the dry gas seals urges the shaft towards the discharge end of the compressor and thus counteracts dynamic forces on the impeller.