What is a Excess Flow Valve (EFV)?

An Excess Flow Valve or EFV, is a device that we can install on your natural gas service line. This is the line that runs from the gas main, generally located in the street, to your house/meter.

EFVs are designed to shut off, or significantly reduce, the flow of natural gas if a service line becomes damaged and that damage causes a sudden and significant increase in gas flow. When activated, the excess flow valve may prevent the buildup of natural gas and lessen the possibility of a natural gas-related safety event.

The EFVs we install are designed to meet the minimum U.S. Department of Transportation performance standards for such devices and are just one of many ways we promote pipeline safety and integrity.