Analytical Techniques for Selection of Repair or Replace Options for Cast IronPiping Systems. Final Report, January 1985-December 1990

摘要

A computerized Cast Iron Maintenance Optimization System (CIMOS) was developedfor use by the gas industry to: (1) identify failure-prone segments of cast iron gas mains; (2) evaluate alternative improvement actions for each segment based on economic and risk exposure considerations; and (3) assess improvement priorities of individual segments using benefit/cost evaluations. CIMOS consists of four interrelated analytical models, a database of inventory characteristics and leak repair histories, and a PC-based user-friendly software system. The analytical models in CIMOS are: (1) leak prediction model, (2) break prediction model, (3) life-cycle costing model, and (4) priority assessment model. CIMOS has been tested at five gas companies. The test results demonstrate that: (1) the CIMOS prediction models can identify failure-prone segments with a high degree of accuracy; (2) a replacement program for cast iron pipes developed using CIMOS recommendations can reduce the frequency of leaks and breaks, the risk of incidents, and the repair and incident costs; and (3) a computerized database needed for CIMOS can be developed at a moderate cost for companies using existing data files.