Abstract:
Universal control circuitry (500) for an electro-hydraulic valve actuator system (105, 105', 105'') includes logic gate circuitry to control one or more of a closing solenoid valve (6), an opening solenoid valve (5), an emergency shutdown solenoid valve (17), and a hydraulic fluid pump (3) motor (2) to route hydraulic fluid through a hydraulic circuit to actuate a valve via a hydraulic actuator (100) according to received commands. The universal control circuitry (500) is configured to control operation for multiple different configurations of a hydraulic valve actuator system including double-acting configurations (105', 105''), single-acting spring-to-open configurations (105), and single-acting spring-to-close configurations (105), 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 (40), and maintained or momentary input commands.
Abstract:
Manual hydraulic override pumps for use with actuators are described herein. An example apparatus includes a manifold including a reservoir port to be fluidly coupled to a reservoir of fluid, a pump port to be fluidly coupled to a pump, a first actuator port to be fluidly coupled to a first chamber of an actuator, and a second actuator port to be fluidly coupled to a second chamber of the actuator. The example apparatus also includes a rotor disposed in a cavity formed in the manifold. The rotor is rotatable between a first actuating position in which the rotor fluidly couples the first actuator port and the pump port, and a second actuating position in which the rotor fluidly couples the second actuator port and the pump port.
Abstract:
Rotary valve actuators having partial stroke damping apparatus are described herein. An example rotary valve actuator described herein includes a housing containing a first piston and a second piston opposite the first piston, where the pistons move in opposite directions to rotate a shaft of the rotary valve actuator. A damper is operatively coupled to at least one of the first piston or the second piston to slow the movement of the piston for only a portion of a stroke of the rotary valve actuator.
Abstract:
The control fluid power apparatus (102) includes a first housing (226) having a first piston (228) defining a first chamber (232) and a second chamber (236), where the first chamber (232) receives a control fluid (220) and the second chamber (236) receives a process fluid (235) from a process system (104). The first chamber (232) is oriented above the second chamber (236) when the control fluid power apparatus (102) is coupled to a control valve assembly (100). A second housing (244) has a second piston (246) defining a third chamber (250) and a fourth chamber (254), where the third chamber (250) receives the control fluid (220) and the fourth chamber (254) receives the process fluid (235). The third chamber (250) is oriented above the fourth chamber (254) when the control fluid power apparatus (102) is coupled to the control valve assembly (100).
Abstract:
An actuator of a process control device continuously monitors actuator force and records high force values at each position point by continuously executing a routine in a processor of the actuator. The routine includes receiving from a position sensor a current position value indicating a position of a valve element in the valve, and from a force sensor a current force value indicating a force applied by the actuator. The routine also includes retrieving, from a memory device coupled to the processor, a previous force value measured at the current position, and comparing the current force values for the current position with the previous force value for the current position. If the current force value for the current position exceeds the previous force value for the current position, the routine replaces the previous force value for the currrent position with the current force value for the current position in memory.
Abstract:
An absolute valve position detector with self-powering capabilities is provided. An energy-harvesting position sensor is activated by the rotation of a pinion that rotates according to the opening and closing of the valve. The sensor outputs an electrical pulse that may be simultaneously used to provide power to the position detector and to indicate the rotation of the pinion and, therefore, the position of the valve. In a preferred example, the energy-harvesting sensor is activated by change in a magnetic field and the magnetic polarization of a Wiegand wire. In examples, the electrical pulse is induced in a coil wrapped around the Wiegand wire when a magnet disposed on the pinion is rotated.
Abstract:
Methods and apparatus are disclosed for automatically detecting the failure configuration of a pneumatic actuator (102). A control module (108) is operatively coupled to the actuator (102), and the actuator (102) is operatively coupled to a valve (104) having a flow control member (110). When a number of pilot valves included in the control module (108) is indicative of a double-acting actuator (102), the failure configuration of the actuator (102) is determined based on the number of pilot valves. When the number of pilot valves included in the control module (108) is indicative of a single-acting actuator (102), the failure configuration of the actuator (102) is determined by comparing a first measurement value obtained in response to moving the flow control member (110) in a first direction to a first position and a second measurement value obtained in response to moving the flow control member (110) in a second direction opposite the first direction to a second position.
Abstract:
Example apparatus for absolute position detection are disclosed. An example apparatus includes a housing and digit gears coupled to the housing to rotate about respective parallel axes. Each digit gear has a first portion including a first set of teeth disposed about an entire circumference of the first portion and a second portion including a second set of teeth disposed about only a portion of a circumference of the second portion. Each digit gear is to correspond to a respective digit in a code representing an absolute position of a shaft. A respective idler gear between each adjacent pair of the digit gears is to be intermeshed with the first set of teeth of one of the digit gears and the second set of teeth of the other one of the digit gears.