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Project in California will develop 128,000 kw in 2-unit underground plant; excavation methods and progress data are given; other major features are: 290 ft high concrete face rockfill dam, underground free discharge valve installation for dam outlet works, underground power tunnel intake valve, etc.

Project in California will develop 128,000 kw in 2-unit underground plant; excavation methods and progress data are given; other major features are: 290 ft high concrete face rockfill dam, underground free discharge valve installation for dam outlet works, underground power tunnel intake valve, etc.

Intensive crevice cor ros ion occurs under rubber gaskets in the valve chambers of carbamate pump cylinders made of austenitic steels 10Kh17N13M3T, 08Khl7N15M3T, and Kh17N13M3B, which frequently causes failure of the seal . Examination of fourteen cylinders made Of austenitic steels af ter 2500-6100 h of operation showed cor ros ion in the intake valve chamber in a band 2 mm wide around the c i rcumference (the diameter of the gasket was 6 mm), the depth of the attack reaching 2 mm. The width of the corroded band in the valve chamber on the discharge side was ~3 mm, with a depth of 1 .5 mm.