Rexa is a regular exhibitor at the GRC Annual Meeting & Expo
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| (Courtesy Rexa) |
Regardless of plant design, everything begins at the Wellhead. Often separated from the plant by significant distances, production wells include Emergency Shutoff Valves (ESVs) and flow control valves – both of which play key roles in the process. Therefore, they need to function reliably to ensure no interruption of the flow of steam or brine to the plant.
A Geothermal power plant in New Zealand recently experienced unstable control of their Production Wellhead valves and sought out REXA - headquartered in Massachusetts, USA - for a solution. The previously-installed pneumatic actuators could not control the valves well enough during both start-up and normal operation. This caused large pressure swings in the process and immense water hammer down the line. Consequently, this resulted in bending pipework and broken pipe brackets – causing unnecessary expenses for repairs.
Leaks within the valves’ stem packing required tightening, making it even harder for the pneumatics to overcome the packing stiction to control the valves. This stiction caused the water hammer as the pneumatic actuator built up pressure in the piston and dramatically jumped up once it overcame the stiction.
