Abstract: An improved pressure balanced choke valve with a reversible cage style trim suitable for installation in production flowlines where it may be desired to later reverse the flow direction and use the well for water injection. The valve body has end connections machined thereon and a central bore for sealingly receiving a reversible cartridge assembly containing the cage style trim. The cartridge assembly is sealed against the valve body cavity by metal-to-metal seals and is easily removed for flow reversal by removal of a simple retainer cap. The cartridge assembly uses an inner sleeve movable within a cage type trim to control the flow. The cartridge is surmounted by a bonnet assembly utilizing a handwheel operated traveling nut assembly to control movement of the inner sleeve.

Abstract: A packoff assembly for sealing an annulus between an inner tubular member and an outer tubular member including a sealing means rotatably connected to a packing nut. The sealing means includes an upper actuation ring rotatably retained on the packing nut. A sealing member having a ring-like metal body is rotatably mounted on the upper actuation ring with a roller ball connection which permits limited relative axial movement between the upper actuation ring and the sealing member. A lower actuation ring is rotatably mounted on the body of the sealing member by another roller ball connection which permits limited relative axial movement between the lower actuation ring and the body of the sealing member. The metal body of the sealing member includes a pair of frustoconical-shaped outer seal lips and a pair of frustoconical-shaped inner seal lips. An elastomeric seal ring is disposed on the body of the sealing member between each pair of metal seal lips.