Wegman valves offers various gas over oil actuators:
Usually end users have a preference for a certain brand of actuators, we work together with all major manufacturers and can offer any desired brand.
The design is based on a hydraulic scotch yoke actuator.
The (natural) gas from the pipeline is not directly used in the actuator but hydraulic fluid is used as an intermediate or transfer to the actuator.
A typical set up includes a high pressure control assembly, hand pump assembly, gas over oil tanks and the hydraulic actuator. The actuator can be single or double acting.
An alternative is direct gas actuator where the gas operates the pneumatic actuator directly.
Rotork, Biffi, Ledeen