Description
Spring return actuators (SD / SZ) work on the principle of the motor being energised the whole time the actuator is holding the valve open. As the actuator rotates, a spring inside is wound up, and the motor then stalls out, holding the valve open. When power is removed from the actuator, the energy in the coiled spring is released, closing the valve and shutting down the actuator.
- Suitable to operate 2 port ON/OFF valves
