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.

A hydraulic actuator having a body defining a chamber, a piston rod including an annular groove and a piston head slidably housed within the chamber, the piston head having a number of segments each of which has a base portion mounted within the annular groove.

A pneumatic actuator and control valve assembly has a housing with a control cavity for a control valve and an actuator cavity for an actuator piston and rod assembly. The control cavity and actuator cavity both have an elongated shape and are substantially parallel to each other. The control cavity has a supply port and first and second control valve outlet ports and at least one vent port with the control valve being movable through the control cavity for controlling communication between the supply port and the first and second outlet ports. The actuator cavity has first and second ports at the retracted and extended ends for shuttling the piston and within the actuator cavity between a retracted and extended end position. The housing has a first inlet and second inlet for passage of pressurized fluid to and from the housing.

A hydraulic actuator is adapted to drive a spoiler of a wing having a flap. When the hydraulic actuator drives the spoiler in an overlapping region where a driving range of the flap and a driving range of the spoiler overlap, an output suppressing structure suppress a drive output of the hydraulic actuator in the overlapping region to be less than that in a non-overlapping region other than the overlapping region.

In a fluid-operated drive for a field device, the drive being designed to set a control valve of the field device, a fluidically operated basic drive is provided with a basic working chamber loaded fluidically and delimited by a basic drive housing part and by a basic actuating piston guided in the basic drive housing part. At least one supplementary drive is provided with a supplementary working chamber loaded fluidically and delimited by a supplementary drive housing part. The basic drive housing part and the supplementary drive housing part are displaceable in one another in accordance with a piston and chamber arrangement so that a volume of the supplementary chamber changes in the event of a relative movement of the drive housing parts.

An actuator arranged to be movable between an extended condition and a compressed condition and being biased to an intermediate condition between and distinct from the extended condition and the compressed condition. The actuator includes a damping device arranged to define the damping coefficient of the actuator. The damping device is arranged to provide a relatively low damping coefficient when the actuator is in a first condition distinct from the intermediate condition, and a relatively high damping coefficient when the actuator is in a second condition, the second condition being distinct from the first condition and being equal or adjacent to the intermediate condition

A multiple-stage fluid operated actuator (100) is provided. The multiple-stage fluid operated actuator (100) comprises a housing (101) including a first bore (212) with a first cross-sectional area and a second bore (215) with a second cross-sectional area. The multiple-stage fluid operated actuator (100) further comprises a piston assembly (210) including a first piston (210a) movable within the first bore (212) and a second piston (210b) movable within the first and second bores (212, 215). The piston assembly (210) separates the first and second bores (212, 215) into a first fluid chamber (214a) selectively in fluid communication with a pressurized fluid source (220) or an exhaust, an airtight second fluid chamber (214b), and a third fluid chamber (214c) selectively in fluid communication with the pressurized fluid source (220) or the exhaust.

Provided are mechanisms and processes for a pneumatic shaft positioning system. According to various examples, the pneumatic shaft positioning system includes a pyrotechnic valve that is configured to control the flow of gas from a pressurized gas source into a pressure chamber. The pressure chamber includes a first piston that is slidably coupled to the pressure chamber. When gas from the pressurized gas source fills the pressure chamber, the piston is configured to slide through the pressure chamber and force a shaft into a predetermined position.

A valve assembly includes a first spool valve that directs fluid to a working object. A second spool valve directs fluid to the exhaust.

A pneumatic actuator and control valve assembly has a housing with a control cavity for a control valve and an actuator cavity for an actuator piston and rod assembly. The control cavity and actuator cavity both have an elongated shape and are substantially parallel to each other. The control cavity has a supply port and first and second control valve outlet ports and at least one vent port with the control valve being movable through the control cavity for controlling communication between the supply port and the first and second outlet ports. The actuator cavity has first and second ports at the retracted and extended ends for shuttling the piston and within the actuator cavity between a retracted and extended end position. The housing has a first inlet and second inlet for passage of pressurized fluid to and from the housing.