The standard also provides a guide to assist the user in specifying electric valve actuators. ISA96.03 – The basic requirements for pneumatic valve actuators of the single ... as spring-return fail ...

Valve positioners compare a control signal to a valve actuator's position and move the actuator accordingly. They are used with both linear valves ... only one side of a single-acting valve actuator ...

Air cylinders are pneumatic linear ... can be single or double action. In a single acting air cylinder, the cylinder contains pneumatic porting for drive in only one direction. Single-action air ...