Abstract: A method and apparatus for monitoring a pipeline expansion joint, in particular the conditions of a pressure-balanced expansion joint. A sensor is positioned so as to sense one or more physical characteristics of a pipeline fluid flow. A signal generated by the sensor(s) is received by a suitably configured electronic controller. The controller, in turn, is connected to a flow control valve, that is movable between at least an “off” or “no-flow” position, and a flow permitting position, connecting a source of compressible medium and the volume confined between the two (or more) balancing bellows of a pressure-balanced expansion joint. An accumulator may also be provided, that may be connectable via the flow control valve, to the confined volume. The controller will be operably configured to cause the valve to be moved, in response to signals received from the sensor(s) that correspond to stored numerical data in the controller that represent different potential operating conditions.

Abstract: Disclosed is a slidable duct assembly for conducting air from a fixed component to a component that is movable with respect to the fixed component by conducting air from a fixed supply of air, associated with the fixed component, to an air delivery member, movable along with the movable component. The duct assembly contains at least two metallic telescoping, tubular conduit sections for rotatably interconnecting the air supply to the air delivery member, and a pair of electrically-conductible, spaced-apart slide bearings positioned between the inner surface and the outer surface of each adjacent conduit section to electrically bond the duct assembly.

Abstract: Disclosed is a flexible joint for sealing two conduits. One half of the joint includes an annular seal gland with an outer surface defining a static seal face. The other half of the joint includes an inner race member having inner and outer bearing surfaces, the inner surface spaced apart from and generally opposing the outer surface of the seal gland and having a region defining a dynamic seal face. An annular bellows constructed of a plurality of convolutions having varying convolution heights is disposed between the first and second seal faces to form a low leakage seal. The heights of the convolutions decrease in the direction of the first to the second seal faces.