Abstract: Methods and apparatus are disclosed for automatically detecting the failure configuration of a pneumatic actuator. A control module is operatively coupled to the actuator, and the actuator is operatively coupled to a valve having a flow control member. When a number of pilot valves included in the control module is indicative of a double-acting actuator, the failure configuration of the actuator is determined based on the number of pilot valves. When the number of pilot valves included in the control module is indicative of a single-acting actuator, the failure configuration of the actuator is determined by comparing a first measurement value obtained in response to moving the flow control member in a first direction to a first position and a second measurement value obtained in response to moving the flow control member in a second direction opposite the first direction to a second position.

Abstract: Methods and apparatus are disclosed for automatically detecting the failure configuration of a pneumatic actuator. A control module is operatively coupled to the actuator, and the actuator is operatively coupled to a valve having a flow control member. When a number of pilot valves included in the control module is indicative of a double-acting actuator, the failure configuration of the actuator is determined based on the number of pilot valves. When the number of pilot valves included in the control module is indicative of a single-acting actuator, the failure configuration of the actuator is determined by comparing a first measurement value obtained in response to moving the flow control member in a first direction to a first position and a second measurement value obtained in response to moving the flow control member in a second direction opposite the first direction to a second position.

Abstract: An example rotary actuator includes a cam that is to be coupled to a valve. The cam is rotatable about an axis. The example rotary actuator also includes a linear actuator having a stem movable along a path offset from and perpendicular to the axis and a chain having a first end and a second end opposite the first end. The first end of the chain is coupled to the stem and the second end of the chain coupled to the cam. The chain is disposed around at least a portion of an outer edge of the cam, and movement of the stem along the path rotates the cam about the axis.

Abstract: An example rotary actuator includes a cam that is to be coupled to a valve. The cam is rotatable about an axis. The example rotary actuator also includes a linear actuator having a stem movable along a path offset from and perpendicular to the axis and a chain having a first end and a second end opposite the first end. The first end of the chain is coupled to the stem and the second end of the chain coupled to the cam. The chain is disposed around at least a portion of an outer edge of the cam, and movement of the stem along the path rotates the cam about the axis.

Abstract: Methods and apparatus for changing actuator output torques are disclosed. An example method includes decoupling a first end cap from a body of an actuator. A first spring assembly is positioned within a first outer chamber defined by the first end cap and the body. A first end of the first spring assembly is positioned adjacent a surface of a first piston. A second end of the first spring assembly is positioned adjacent the first end cap when the first end cap is coupled to the body. The method includes positioning a first spacer within the first outer chamber and coupling the first end cap to the body. The first spacer changes a distance between the first and second ends of the first spring assembly when the first end cap is coupled to the body to change an output torque of the actuator.