Reliability Improvements in Deepsetting Lineshaft Pumps for Geothermal Service

Abstract

Several 1000 ft. long, 600 hp, high capacity (1320-1750 gym) 18 and 20 stage, motor driven lineshaft pumps, have been in 360F geothermal brine service at Heber, California since May, 1985. Shortly after startup in 1985, significant reliability problems were encountered with both mechanical shaft seals and hydraulic bowl sections of these pumps. Numerous design and material changes were implemented during the next year of operation. These changes, tougher with careful shop assembly and inspection, improved field assembly, and continuous on-stream condition monitoring, have more than tripled the average life of all pumps. Mechanical seal life has also improved dramatically. Single flexible stator certified type seal designs are successfully in service today. Modified pumps continuous to run satisfactorily today with no signs of performance deterioration. Reliability improvement demonstrated over the past year support our believe that pumps in this difficult service and be expected to proved a minimum of nine months continuous service A companion paper by Mr. K.M. Auyeung of Chevron Resources Company covers operations and repair procedures developed to improve pump reliability