Abstract: A system for reducing the initial force required to actuate a valve, preferably a rotary valve, from its fully closed position is disclosed. The system comprises an operating arm fixed to and rotatable with the valve stem. Disposed and rotatable about, but not fixed to, the valve stem is a spur gear with an operating lever affixed thereto. The force applied to the operating lever is transferred to the operating arm through a gear sector carried on the operating arm. During the initial actuation, the gear sector engages with and rotates about a latch pin to increase the force applied to the operating arm by the operating lever. During the remainder of the actuating movement, the gear sector is fixed relative to the operating arm so that the force applied to the operating lever is transmitted to the operating arm without any increase in force.

Abstract: The present invention is directed to an improved driver for operatively connecting an actuator to a rotatable valve member disposed in the fluid path of a valve housing. The improved driver of the present invention comprises a drive shaft for connection at one end with an actuator and having a yoke connected to the other end of the drive shaft. The yoke preferably comprises two arms extending on opposite sides of the fluid path through the valve housing. Each arm includes a contact member, e.g., a dog or set screw extending from the arm, for engaging and turning the rotatable valve member while not rigidly connecting the arm with the valve member. In a preferred embodiment, the arms of the yoke extend around the fluid path and are joined together with a trunnion to aid in centering the driver and rotatable valve member.

Abstract: The present invention is directed to an improved valve comprising a valve housing, a fluid path therethrough, a seat disposed about the fluid path, a rotatable, curved wedge disposed in the fluid path, an actuator for rotating the wedge between its closed and opened positions and a fixed member for displacing the wedge longitudinally toward the seat as it is rotated between its opened and closed positions. Preferably, the seat is biased toward the hemi-wedge. The rotatable, curved wedge has a curved sealing surface for cooperation with the seat. The wedge includes a bore through its thinner end forming a part of the fluid flow path when opened while its thicker end blocks the fluid flow path in the closed position. The sides of the wedge are curved, one side providing a convex sealing surface and the other side providing a concave thrust surface.

Abstract: The present invention discloses an apparatus and method for periodically and automatically introducing fluid into a producing well through a tubing drain valve in the production tubing. The apparatus and method of the present invention employ a tubing drain valve actuated to its open position by pressurizing the interior of the production string. The system further includes apparatus for introducing a fluid, e.g., a paraffin solvent or formation treating chemical, into the production tubing and into the formation through the opened tubing drain valve. After completion of this operation, the tubing drain valve is closed and production resumed by a mechanical actuator, preferably an actuator carried by the sucker rods for operating the downhole pump. A control device, including optional monitoring devices, provides a system for introducing such fluids at periodic intervals.

Abstract: The present invention discloses a tubing drain valve suitable for use in a borehole and a method for operating the disclosed valve. This device is particularly useful in a production pipe string where it provides a convenient apparatus and method for draining production fluid from the string in order to facilitate a variety of activities. More particularly, the present invention relates to a tubing drain valve actuated to its open position by a force developed across the working surfaces of a movable piston by the pressure in the interior of the production string and actuated to its closed position by a mechanical device. Preferably, the tubing drain valve of the present invention further comprises structure to bias the valve to its closed position and structure to bias the valve in its open position. The valve of the present invention is actuated by overcoming the appropriate biassing forces.

Abstract: The present invention is directed to an apparatus and method for providing a tubing drain valve suitable for use in a borehole. The present invention is particularly useful in connection with production strings employed in wells producing heavy, sand-bearing oils. The invention comprises a tubing drain valve operable independently of any action or condition on the interior of the pipe string. The tubing drain valve of the present invention is opened in response to the pulling of the pipe string from the borehole. A plurality of dogs carried by a sleeve biased to an initial position about a tubular member suitable for incorporation in a pipe string and including a valved passage through the side wall thereof are designed to engage the casing and temporarily prevent movement of the sleeve as the pipe string is being pulled from the borehole. Continued pulling of the string produces relative movement of the sleeve and tubular member along the longitudinal axis of the tubular member.

Abstract: A well pump having a power fluid that is to be reciprocated in a conduit so as to power a downhole pump by filling the downhole pump and the lower portion of the power conduit with a hydraulic oil having a specific gravity greater than water and filling the rest of the power conduit with a less compressible fluid such as water.