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Excess Flow Valves

Safety at the service level.

An Excess Flow Valve (EFV) is a mechanical safety device installed inside a gas service line between the gas main in the street and the gas meter. The EFV is designed to minimize the flow of natural gas in the event of a service line break. A potential benefit is, in the event that an excavator accidentally digs up the gas service line, the valve would operate to minimize or shut off the flow of gas.

side of Unitil natural gas truck

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