Reliable and cost saving shutdown protection for underground gas storage project in China

Self-contained emergency shutdown systems installed at wellhead where external power sources are not available.

China National Petroleum Corporation (CNPC) has selected Bettis™ PressureGuard™ self-contained hydraulic shutdown systems from Emerson Process Management for installation on the Dazhangtou natural gas storage reservoir project in Tianjing, China. Seven PressureGuard systems, which require no external power source, will protect the gas storage reservoir by closing gate valves when a high or low pressure threshold has been reached.

The Dazhangtuo reservoir is the first gas storage facility in China. It strengthens the peak-gas adjustment capacity of the Shan-jing natural gas pipeline, which extends 585 miles from Yulin, Shanxi, to Beijing. Gas that is not needed immediately is diverted into underground storage facilities. This allows excess gas delivered during the summer to be made available to help meet the increased demand in the winter.

The Bettis PressureGuard systems are being installed in the wellhead area of the gas storage facility, where there is no electrical power. This is an ideal application for the spring-based PressureGuard shutdown systems because no plant air, fuel gas, electricity, or expensive nitrogen back-up systems are required. A self-contained oil reservoir also removes the need for any external hydraulic piping. A Pressure Pilot with Hi-Hi, Low-Low options triggers the system when a pressure threshold is reached.

The Bettis PressureGuard system offers built-in temperature compensation and pressure relief and has proven to be highly successful in years of field service under some of the most demanding operating and environmental conditions. The actuator can be used with either rotary or linear spring-return hydraulic operators to provide a fail-safe system adaptable to ball, plug, and other quarter-turn valves as well as reverse-acting gate and other linear operated valves.