Abstract: A rotary bi-directional valve actuator having a new and improved dual ratchet mechanism. The linkage maintains the pawl disengaged or uncoupled from the drive bushing until operated to protect the ratchet mechanism and to prevent its binding or jamming. The disengagement of the mechanism compensates for inadvertent rotational movement of the valve stem which could result in malfunction or damage to the actuator when actuated. The actuator is extremely rugged and durable in construction for a long operating life. The simplified construction of the actuator is also easy to maintain and easy access to the working parts is provided by the sealed housing.

Abstract: A choke is provided having a stationary tubular flow nozzle with throttling ports formed through its side wall. A movable tubular throttling ring may be moved over the nozzle to restrict or close the ports. The required liquid-tight seal or shut-off is obtained with annular seal surfaces formed on the nozzle and ring but remote from and upstream of the ports, so that erosion of these seal surfaces, by the high velocity streams passing through the ports, is minimized.

Abstract: A new and improved valve apparatus having an operating mechanism sealed in such a manner that the fluid pressure urging thereon produces offsetting or balancing forces to enhance ease of valve operation. To accomplish the force balancing, the flow closure means is continuously sealed to the valve housing and seat to produce the desired pressure responsive surfaces. By balancing the pressure forces, movement of the valve closure element between the open and closed positions with a minimum of operating force is accomplished. In addition the operating mechanism tubular flow closure element and valve seat having a plurality of opposed radially disposed flow opening are arranged so that the controlled flow through the openings into the seat impinges on itself to prevent flow cutting or erosion of the valve seat. When the flow closure element moves to the closed position, it activates a protected second seal on the seat to block flow throuh the flow openings.

Abstract: A fluid flow control valve especially adapted for use during well drilling operations as a drilling choke is disclosed. A replaceable ported seat and movable tubular flow control element cooperate to control flow through the angled body valve housing. The flow closure mechanism is operating fluid pressure balanced for ease of valve operation during extreme pressure working conditions. Internal flow control working parts of the valve are rugged in construction and assemblage. The portions of the valve subject to wear or flow erosion are also easily replaced when required. An indicator is arranged to signal incipient failure of the replaceable parts of the valve in order that they may be replaced prior to the occurrence of a major failure.

Abstract: An orifice flow control valve is provided with a set of disks mounted in the body of the valve. A downstream disk is mounted in a fixed position in the valve body and an upstream disk is rotatable in the valve body and in face-to-face engagement concentric with the downstream disk. There are holes in the downstream disk and in the upstream disk for control of the amount and direction of flow of fluids through the valve. When the valve is in a position between fully open and closed, there are at least two streams through the disks which impinge on each other for providing a resultant stream flowing generally parallel to the axis of the valve.

Abstract: Reset means to advance a valve spool from a first valve seat to a second valve seat in opposition to exceedingly high biasing fluid pressure comprises a manually rotatable actuating means in screw threaded engagement with the body of the pilot valve. With the manually operable actuator at its retracted position, means is manually operated to operatively connect the manual actuator to the valve spool to permit advance of the manual actuator to drive the valve spool from the first valve seat to the second valve seat against the resistance of the biasing fluid pressure.