《EPRI - SF6 Management Program》.pdf

EPRI’s SF Management Program 6 Ben Damsky EPRI 3412 Hillview Avenue Palo Alto, CA 94304 Introduction Sulfur hexafluoride (SF6) gas is widely used in circuit breakers and gas-insulated substations, but its use presents safety and environmental challenges when maintenance is needed. Utilities using SF6 gas have a variety of needs, including best practices for handling SF6, new tools for detecting and mitigating leaks, and information on assessing gas purity. In recent years, EPRI has conducted research and developed tools to meet these needs. The tools will assist utilities in adopting handling procedures that are safe, economical, and environmentally sound; detecting leaks cost-effectively and reducing the cost of replacement gas; and evaluating gas quality. Background SF6 gas has a number of qualities that make it useful as a dielectric medium for electric utility applications. It has a high dielectric strength, is not corrosive to metals at ambient temperatures, and is chemically and thermally stable, nontoxic, and nonflammable. Utility applications of SF6 began in the United States in the 1950s. Since that time, the gas has progressed to be the main dielectric and insulator for circuit breakers, disconnect switches, gas-insulated busbars, and distribution equipment. Several million SF -filled 6 units are estimated to be currently in service. Annual SF production is approximately 8 6 million kg. Although pure SF6 is chemically inert and saf