These devices are electromechanically operated valves designed to control the flow of fluids or gases within a system. They employ an electric current through a solenoid to generate a magnetic field, which in turn actuates a mechanical mechanism to open or close the valve. A critical feature incorporated into certain designs is a mechanism allowing for physical, non-electrical operation. For example, in a pneumatically controlled industrial process, the device might normally be electrically switched to direct airflow to an actuator. However, if power is lost, a user could manually engage the override to shift the valve’s position, ensuring continued, albeit manually controlled, operation.
The inclusion of this manual function enhances system reliability and safety. It allows for the maintenance of critical processes during power outages or electrical system failures. The ability to take direct control circumvents dependency on electrical power, providing a failsafe mechanism. Historically, the need for manual control options arose from early automation systems that lacked robust backup power solutions. Modern systems continue to utilize this feature as an added layer of operational security, ensuring the ability to perform essential tasks even when electrical control is compromised. This is particularly vital in applications where system downtime could lead to significant economic losses or potential hazards.
