Provided are: a valve control device which is capable of reducing the difference between a set opening amount and the actual opening amount, when executing a partial valve stroke test; a valve control system; a method for calculating a valve control coefficient; and a valve control method. This shut-off valve control device is provided with a microcomputer for controlling the opening and closing of a solenoid valve which supplies air from an air supply source, to a cylinder of an air cylinder for controlling a valve shaft of a shut-off valve, and discharges said air. The microcomputer acquires a set opening amount of the shut-off valve. Furthermore, the microcomputer controls the solenoid valve to a value obtained by dividing the acquired set opening amount by a predetermined coefficient C.

To generate a setpoint signal to stroke a valve during a partial-stroke test, a first target is determined for the setpoint signal based at least on a travel displacement threshold, the travel displacement threshold corresponding to a desired extent of travel of the valve during the partial-stroke test; the setpoint signal is ramped from an initial value to the first target, during a first time interval; subsequently to the first time interval, the setpoint signal is maintained at the first target during a second time interval; a second target is determined for the setpoint signal based at least on the initial value; and during a third time interval subsequent to the second interval, the setpoint signal is ramped from the first target to the second target in a direction opposite to the ramping of the setpoint signal during the first time interval.

To generate a setpoint signal to stroke a valve during a partial-stroke test, a first target is determined for the setpoint signal based at least on a travel displacement threshold, the travel displacement threshold corresponding to a desired extent of travel of the valve during the partial-stroke test; the setpoint signal is ramped from an initial value to the first target, during a first time interval; subsequently to the first time interval, the setpoint signal is maintained at the first target during a second time interval; a second target is determined for the setpoint signal based at least on the initial value; and during a third time interval subsequent to the second interval, the setpoint signal is ramped from the first target to the second target in a direction opposite to the ramping of the setpoint signal during the first time interval.

Device (10) for converting a linear motion of a first mechanical element in a rotary one of a second mechanical element, having a pin (1) which realizes a coupling between the two mechanical elements, a guide block (3) housing the pin (1) and having inclined outer side surfaces (3), two guide pads (5) provided with corresponding inclined inner side surfaces (5), which are coupled with the inclined outer side surfaces (3) of the guide block (3), and with outer side surfaces (5) configured to be coupled with corresponding wings of the Scotch yoke (9), a spring element (6), configured to generate an elastic force (Fe) on the guide pads (5) such that the guide pads (5) slide on the guide block (3), wherein the inclined outer side surfaces (3) of the guide block (3) and the inclined inner side surfaces (5) of the guide pads (5) have the same inclination angle, the distance (A) between the outer side surfaces (5) of the guide pads (5) is a function of the mutual position of the inclined inner side surfaces (5) of the guide pads (5) and the corresponding inclined outer side surfaces (3) of the guide block (3), and the outer side surfaces (5) of the guide pads (5) are parallel to each other.

Embodiments of the invention provide an actuator (100) for a valve assembly. The actuator can include a yoke (146) with at least one bore (196), a first rod assembly (136), and a first slide member (148) seated within the at least one bore and pivotally connected to the first rod assembly. The yoke can be configured to rotate about a yoke axis (198) to actuate the valve assembly. The first rod assembly can be configured to move in a first direction transverse to the at least one bore and the yoke axis. The first slide member can be configured to slide telescopically within the at least one bore as the first rod assembly moves in the first direction to transmit torque to the yoke for actuation of the valve assembly.

The disclosure relates to exemplary embodiments for a combination device configured to effect lockout and partial stroke testing for an actuator having a piston rod providing linear motion and connected to a guide block in an actuator, wherein the combination device includes a device housing having a housing bore, wherein the device housing is adapted to mount on a receptacle on the actuator that aligns a device housing bore coaxially to the translatory motion axis of the piston rod; an extension rod attached to the guide block connected to the piston rod; at least two slides or a profiled bore index sleeve disposed in the device housing that when engaged provide means of restraining the movement of the extension rod in a manner that prevents said extension rod and a driver element of the actuator from rotating, relative to an actuator housing; a housing cover mounted over the device housing wherein the housing cover protects and retains the extension rod, and the slides or the index sleeve in the device housing and a spring biased safety pin mounted on the housing cover wherein the spring biased safety pin is configured to prevent unintended actuation of the actuator; and a tubular cover to protect the extension rod.

A valve actuator device includes a supporting body, a driving shaft, and a fluid cylinder having a body connected to one side of the supporting body. The cylinder has a rod that controls rotation of a driving arm rigidly connected to the driving shaft. Linear movement of the rod is converted into rotation of the driving arm by engagement of a cam-follower pin carried by the rod within a slot formed in the driving arm. The slot is formed in an insert that constitutes an element separate from the driving arm body and that is received and held within a seat of the driving arm body. Thus, a single main body for the driving arm is provided, having a plurality of inserts for selective mounting within the seat and are differentiated from one another in the dimensions and shape of the slot and/or in the material of the insert.

An improved structure of a pneumatic actuator is direct to the pneumatic actuator and a signal transmitter connected thereof and the respective shaft cores are integrated to be one. An assembly slot integrated with a body is spaced on the upper portion of the body of the pneumatic actuator and at the shaft line corresponding to the shaft core, for the signal transmitter to be installed inside the assembly slot. A shaft hole is installed at the position of the bottom of the assembly slot corresponding to the shaft core and the shaft core passes through the body of the pneumatic actuator and the interior of the body via the shaft hole. The assembly slot is covered by a cover plate. Through such a configuration, the originally independent and separated signal transmitter and pneumatic actuator are integrated, thereby ensuring the consistent perpendicularity and concentricity of the shaft cores thereof. Meanwhile, the integration of the signal transmitter and pneumatic actuator can reduce components and save labor for assembly.

Universal control circuitry for an electro-hydraulic valve actuator system includes logic gate circuitry to control one or more of a closing solenoid valve, an opening solenoid valve, an emergency shutdown solenoid valve, and a hydraulic fluid pump motor to route hydraulic fluid through a hydraulic circuit to actuate a valve via a hydraulic actuator according to received commands. The universal control circuitry is configured to control operation for multiple different configurations of a hydraulic valve actuator system including double-acting configurations, single-acting spring-to-open configurations, and single-acting spring-to-close configurations, each with or without an emergency shutdown arrangement (which may be configured to trip based on an external shutdown input alone or in combination with a local system power failure), a hydraulic accumulator, and maintained or momentary input commands.

A modular actuator assembly which can be used for partial stroke testing of a valve, the assembly having a force module and a tandem piston module. The force module has a primary piston and piston rod interconnected to a shaft which is movably mounted therein. The tandem piston module is connected to the force module and has a tandem piston and piston rod. An indicator plate is connected to the piston rod and is selectively positionable on the tandem piston rod. The tandem piston rod extends into the force module and acts as a pneumatically engaged hard stop for preventing spurious travel of the primary piston and hence spurious valve travel.