Abstract: A changeover valve which accommodates thermal transients and is operable over a range of temperatures includes a crossover member (20) and a seat assembly (30) in each outlet passage (15), a thrust bearing (45) rotatably supporting the crossover member and a split load ring (40) comprising an inner ring (142) and an outer ring (146) threaded into the changeover valve body. A wave spring (150) is disposed between the inner and outer ring. The loading on the wave spring can be adjusted by the threaded in outer ring, which in turn adjusts the force of engagement of the crossover member against the seat assemblies.

Abstract: A changeover valve system is provided that is adapted to be secured at one end to a riser from a pressurized piping system and at its opposite end to at least two pressure relieving devices. The changeover valve system includes a body and at least two elbows secured to the body to which are attached at least one of the pressure relieving devices. A partially spherical changeover member is provided within the body having at least one inlet port adapted to communicate with the riser and at least one and preferably two outlet ports adapted to alternately communicate with either of the pressure relieving devices. Transport means are provided for effecting rotation of the changeover member within the body to cause the changeover member to travel from one position wherein an outlet port is in communication with one of the pressure relieving devices to a second position wherein an outlet port is in communication with the other pressure relieving device.

Abstract: A changeover valve system is provided that is adapted to be secured at one end to a riser from a pressurized piping system and at its opposite end to at least two pressure relieving devices. The changeover valve system includes a body and at least two elbows secured to the body to which are attached at least one of the pressure relieving devices. A partially spherical changeover member is provided within the body having at least one inlet port adapted to communicate with the riser and at least one and preferably two outlet ports adapted to alternately communicate with either of the pressure relieving devices. Transport means are provided for effecting rotation of the changeover member within the body to cause the changeover member to travel from one position wherein an outlet port is in communication with one of the pressure relieving devices to a second position wherein an outlet port is in communication with the other pressure relieving device.

Abstract: There is provided a seat assembly adapted to be received in a spool bore of a valve having a fluid controlling member for controlling the flow of fluid through the valve, with the spool bore having a threaded interior portion. The seat assembly includes a first member having, located towards one end thereof, a grooved ring adapted to receive a tool, and a threaded exterior portion which is adapted to threadedly engage the interior threaded portion of the spool bore. The seat assembly further includes a second member adapted to be received in the first member, with the second member having a seat face adapted to contact the fluid controlling member. The first member threadedly moves the second member between a first position where the seat face contacts the fluid controlling member of the valve to a second position where the seat face is remote from the fluid controlling member of the valve.

Abstract: A valve assembly is provided which is particularly suitable for operation and maintenance under extreme environments. It includes a valve body, a ball valve member rotatably mounted within the valve body, a bonnet removably secured to the valve body, and seat retaining asemblies removably secured to the bonnet. Upon removal of the bonnet, the valve member and all internals are also removed as a unit so that they may be serviced at a convenient location. The seat retaining assemblies may include inclined surfaces which seat against oppositely inclined surfaces defined within the valve body. An alignment plate is secured to the seat retaining assemblies to insure proper sealing.

Abstract: A swing check valve which includes a valve body having an inlet and outlet. A recess in the valve body designed to hold a seal ring and a check valve disc swingable between open and closed positions. The disc is supported by a high strength wire secured at one end in a support spacer pinned through bearing blocks fixed to the valve body and at its other end in a groove formed on the outer peripheral surface of the disc. The parts are designed and chosen such to provide a lightweight valve disc which is held open by minimum velocity of fluid flowing through the valve which thus reduces oscillations and accompanying wear of bearings supporting the valve operating parts.