SM - Stepper motor actuator


The Stepper Motor (SM) actuator has an internal mechanism which is arranged to be interfaced to the female thread of the threaded valve stem. Two hydraulic or pneumatic actuators drive the rotation of the internal mechanism of the stepper motor, one clockwise and the other anticlockwise, thus allowing the rotation in defined steps and the linear movement of the threaded rod.

SM actuator is available in two different versions:

  • Hydraulic (SMH)
  • Pneumatic (SMP)

Hydraulic actuators is without internal springs, one spring allows the return of both hydraulic/pneumatic actuators.
Both hydraulic and pneumatic version driven in both directions to provide control.


    • Available in different sizes to meet different torque requirements
    • Available with two 3-way solenoid valve and other accessories
    • Direct connection between position transmitter and valve stem without intermediate mechanism
    • Linear and visible stroke indicator
    • Manual override detachable/attachable (user defined)
    • Manual override provided in case of loss of mechanism forces


Operating pressure

70 bar to 250 bar (oil)

4 bar to 10 bar (air)

Standard operating temperature

-20°C to 70°C

(lower or higher temperature on request)

Standard supply medium

Oil, instrument air

Output torque

Up to 400 Nm


Up to 4" (100mm)

Internal mechanism

15 step / turn