Emerson Process Management has expanded its WellGuard linear valve actuator with the introduction of the model HWG. This hydraulic, piston-operated actuator, ideal for use on oil and gas wellhead Christmas trees and on production flow lines, provides an added dimension and complement to the WellGuard pneumatic piston and diaphragm actuators that have already gained wide industry acceptance for their service reliability. The WellGuard HWG actuator provides open and close controls for major brands of API 6A through-conduit reverse-acting gate valves and can be used with API 6D and ANSI B16.34 valves where the bonnets are built to the Bettis design. The HWG is rugged and well suited for use in harsh environments, such as H2S and CO2. The HWG actuator is designed for either onshore or offshore use.