🔍 Key Concepts

• Electric valve actuator safety devices: difference between torque switches and limit switches in protecting the motor and valve • Open vs. close travel: which protection is normally used to stop travel at the fully open position versus to protect against over‑seating when closing • Mechanical vs. electrical shutoff: which options in the choices act electrically on the motor circuit and which are purely mechanical/manual

💭 Think About

• When a valve is being opened under normal conditions, what determines the point at which you want the motor to stop: a position setting or a torque limit? • Which device in an actuator is usually set to protect the valve and motor from excessive force when the valve is being driven tightly shut, and which device is used simply to stop motion at the end of stroke? • Looking at the illustration, which components are wired into the control circuit to interrupt power to the motor automatically, and which only act if an operator intervenes or a mechanical part is disengaged?

✅ Before You Answer

• Identify which options are electrical switch devices that can interrupt the motor circuit automatically during normal operation. • Decide which protection is normally dominant during the opening stroke of a valve in an electric actuator: position‑based or torque‑based. • Verify that the option you choose does not rely on manual action or physical disengagement of gears to stop the motor in ordinary valve‑opening operations.