Langley Alloys has supplied large quantities of Alloy 2205 plate to CalEnergy's Salton Sea geothermal plants, where it provides acceptable corrosion resistance for pipework and treatment units in the cooler areas of the process.
The Salton Sea geothermal field
CalEnergy, part of BHE Renewables, operates 10 generating plants in the Salton Sea Known Geothermal Resource Area in Southern California's Imperial Valley. This active geothermal zone runs along the San Andreas Fault, where geologic forces bring the Earth's natural heat near the surface, creating one of the world's most powerful geothermal hot spots. The reservoir extends beneath the Salton Sea, where underwater vents release steam that rises in boiling circles of bubbles on the lake's surface. Production wells tap superheated water reservoirs thousands of feet down; the released pressure drives the hot water to the surface, where steam is separated and used to drive turbines and generate electricity.
Material selection
The individual plants were developed between 1982 and 2000 and generate around 330MW of power. After more than 30 years of operation, CalEnergy is investing over $1 billion in improvements to sustain its Salton Sea operations for another 30 years and to consider further capacity expansion.
Langley Alloys has supplied large quantities of corrosion resistant alloys in plate form, predominantly Alloy 2205, used to fabricate pipework and treatment units. Super duplex alloys such as Alloy 32750 have replaced the original Alloy 625 material with significant savings, while Alloy 2205 has shown acceptable corrosion resistance in areas of the plant where the geothermal fluid temperature has dropped below 180degC/370degF.