Depending upon the actuation mechanism mechanical valves is categorized as the ones which get actuated mechanically. Unlike solenoid valve where the valve gets actuated due to actuation of solenoid coil or the air-operated valve where the valve gets actuated due to external pilot, mechanical valves are actuated by the application of external force as to cause of actuation. Some of the mechanical valve types are roller lever valve, one-way roller lever valve, toggle lever valve, etc.