In 2012 the government in China initiated an incentive policy to encourage the country's valvemaking industry to develop its own subsea valves to serve a market that has been traditionally dominated by foreign manufacturers. Through its factory in China, Rotork Gears has been working closely with the Chinese valvemakers involved with subsea valve production to provide technical and engineering support, drawing on over 30 years experience of subsea gearbox design and manufacture. Early in 2013 these efforts were rewarded with an order from the Shanghai Pudong Hanwei Valve Company.
The contract involves two WGS Series subsea gearboxes fitted to a double block and bleed valve for a natural gas pipeline in the Bohai Sea. The 8 inch Class 600 valve is being installed a depth of 30 metres on a pipeline serving the Suizhong SZ36-1 oilfield and operated by the China National Offshore Oil Corporation (CNOOC).
Designed for heavy duty subsea applications, the Rotork WGS quarter-turn gearbox features a worm shaft supported on taper roller bearings, a high strength alloy steel worm screw and a membrane or piston type pressure compensator to enable operation at any depth. Gearboxes can be equipped with a high visibility position indicator, vertical or horizontal ROV inputs and a handwheel for diver operation. Self locking and available with many gearing ratios, WGS gearboxes are permanently lubricated and designed for output torques of up to 500,000 Nm.