Abstract

The first buried asbestos-cement (Transite) pipeline used in high temperature (approximately 300/sup 0/F) service for transport of geothermal fluids was installed in the fall of 1975, and has seen 1/sup 1///sub 2/ years of service. The line is 4000 ft long, between the deep geothermal wells No. 1 and No. 2, in the Raft River Valley of Idaho. The experience in using this pipeline has been satisfactory, and methods have been developed for minimizing the thermal expansion/thermal shock breakage problems. Recommendations on improved design and construction practices for future pipelines are given. The substantially reduced cost (factor of 2) of an asbestos-cement pipeline compared to the conventional steel pipeline, plus the esthetically desirable effect of a buried pipeline dictate adoption of this type as standard practice for moderate temperature geothermal developments. The Raft River Geothermal Project intends to connect all future wells with pipelines of asbestos-cement, insulated with 1 to 2-inches of urethane, and buried between 2 and 3 ft. Total cost will be approximately $110,000/mile for 10-inch diameter pipe, $125,000/mile for 12-inch diameter. Document type: Report

Abstract

Asbestos-cement (Transite) pipe was installed at the Raft River Geothermal Area in the fall of 1975 and has been used extensively since. The pipe is used to transfer water from the well sites to the testing areas, reserve pits, and reinjection wells. The pipeline was designed to transport approximately 300 F water at 150 psi over a period of time for the present testing program and later, for the 5 MW(e) Raft River Pilot Plant. Numerous line failures have occurred since the original lines were installed. Due to the various causes of the line failures and the extensive downtime which has occurred because of them, further examination of Transite pipe is necessary to determine its future use as completion of the 5 MW(e) pilot plant approaches. The Conversion Technology and Engineering Branch has completed a preliminary study of the effects of SI however, no funding is presently available due to limitations in the budget for the 5 MW(e) pilot plant project. The Mechanical Design Branch is continuing design analysis in an effort to gather information to determine maximum warmup rates for the S&I system. Document type: Report