Control cabinets

In order to open and close valves (e.g. ball valves or butterfly valves), a control unit and an actuator (usually a cylinder) are required. Various valve types are installed in the control unit, which enables a variety of safety and logic functions.

A distinction is made between gas-direct controls, where the pressurised natural gas is used directly as the control medium and no further auxiliary energy is required, and electrohydraulic and gas-over-oil controls.

For emergency operation of a drive, such systems often have a hand pump with an integrated (oil) tank. Actuator controls are used for safety-related operation of shut-off valves and are referred to as ESD controls.