Excess Flow Valve Regulation

Effective April 14, 2017, federal natural gas safety regulations require the installation of an Excess Flow Valve (EFV) on all new or replaced natural gas service lines to residential and small commercial customers whose total appliance load is no greater than 1,000 cubic feet per hour. The regulations also allow certain existing residential and small commercial customers to request the installation of an excess flow valve on their natural gas service lines.

An excess flow valve is a safety device designed to significantly reduce the flow of natural gas in a service line that has been broken between the gas main and gas meter. The decreased flow of natural gas reduces the risk of personal injury and property damage that could occur if the escaping gas ignites. However, an excess flow valve is not designed to protect against minor gas leaks on the service line or gas meter, or any leak on customer piping inside a home or business.

Typical Causes of Broken Service Lines

The illustration shows some typical causes of broken service lines, including excavation damage. Remember, the best prevention against damaging your service line is to have all below ground utility lines marked before digging. This free service is available by calling Tennessee811 at 811 (800-351-1111).

Excess Flow Valve Diagram

Excess Flow Valve Diagram

Request Installation

Current residential and small commercial customers, whose total appliance load is no greater than 1,000 cubic feet per hour, approximately 1,000,000 BTU (British Thermal Unit) per hour, may request Clarksville Gas and Water (CGW) to install an excess flow valve in their service line if one does not already exist. Per city code, customers requesting the installation of an excess flow valve will be responsible for the payment of the actual cost associated with the installation of the excess flow valve and cost associated with the maintenance, if any, of the excess flow valve. The estimated minimum cost for installation of an excess flow valve in an existing service line is $700, but the actual cost may be substantially greater depending on the site circumstances or conditions.

If you are interested in having an excess flow valve installed in the service to your home or business or would like more information, please contact a Clarksville Gas & Water representative at 931-645-7400 or email Gas and Water. A Clarksville Gas & Water representative will research the technical requirements of the excess flow valve for your service line, answer any questions you may have regarding excess flow valves, and can work with you to establish an estimated time for installation.

Additional Information

For more information, view the Pipeline and Hazardous Materials Safety Administration Notice on Excess Flow Valve in Gas Distribution Systems 49 CFR 192.383(a) (PDF).