The valves are the only moving part of a conduit installation and may be operated manually or by means of mechanical switches operated by a computer or any other electronic system.
Valves (and bypasses) may be operated electrically or pneumatically, i.e. the force which makes the gate close may either be an electrical motor or compressed air, via an electro-pneumatic valve. In all events an electrical signal is required which may be of 12/24 110/220 volts in DC or AC.
The fitting of end of section units which emit an electrical signal when the valve is totally closed is also possible. The switches may be simple (using a spring to maintain the normal closed position) or with a double effect (there is no default position when there is no load).