GH and GHL-Series gas-over-oil (gas/hydraulic) valve actuators use high pressure process gas to provide the energy required to power the valve actuator automating the valve. To provide increased safety and reliability, the process gas acts upon hydraulic fluid stored in gas-over-oil tanks, creating hydraulic pressure that is subsequently used to power the hydraulic valve actuator. As standard, the gas-over-oil control system provides local open and close control using either the high pressure process gas, or via a hydraulic hand pump. Numerous additional control system options are available; including linebreak detection (rate of drop and high/low) and remote control.
Automation of rotary and linear valves in gas transmission lines.