The Shafer SH Series of gas-over-oil valve actuators from Emerson Process Management are suited to automate valves used for gas transmission as well as at compressor stations, gathering plants, storage facilities, meter runs and many other applications. Designed for 50 years of operation, the actuator has a 15-year seal life and a 10 year, industry-leading warranty. The SH series actuator is operated by hydraulic oil, pressurized by the pipeline gas. Powering the actuator with oil prevents the internal corrosion associated with other actuator designs. The actuator is designed so the gas is contained within two tanks, half filled with hydraulic oil. Contaminants and moisture in the gas settle to the bottom of the tank where they can be drained. The actuators can be used for standard on/off service or as part of an Emergency Shutdown System. Three sizes are available to suit 2in to 8in valves with a torque range between 2250in-lbs and 18,000in-lbs. The helical spline technology contained within the actuator does not cause stem side loading, which other designs can be prone to do. Stem side loading can cause premature packing or seal wear and leakage. The SH series is powered by pipeline gas in the pressure range of 400 to 1500PSIG. It is also possible to operate the actuator manually when required, for example during commissioning or in situations where pipeline pressure is not available.
