Evaluation of Joint Repair Methods for Cast Iron Natural Gas Distribution Mains and the Preliminary Development of an Alternative Joint Seal

摘要

Low pressure cast iron natural gas distribution mains are beneath most streets in older sections of most cities. A major portion of the maintenance budgets of all natural gas utilities operating in older cities is the cost of repairing leaks from old cast iron low pressure mains. In an attempt to reduce maintenance costs, the Consolidated Edison Company of New York has funded research to develop a main sealing method that is more effective and economical than currently available systems. Phase I of this research program was to evaluate all existing and previously-attempted leak sealing methods and to determine those factors that are critical in a method's success or failure. As a result of Phase I, Phase II will develop a mechanical seal capable of being emplaced on the inside of the main while still maintaining a flow of gas in the main.