Oneonta Utilities Board

Excess Flow Valves

What is an excess flow valve?

An Excess Flow Valve, or EFV, is a device that automatically closes and restricts the flow of natural gas if an underground pipe is broken, completely cut, or torn apart. Such damage usually results from some type of excavation or digging. An EFV may also restrict the flow if the gas meter is damaged for some reason.

What does an EFV do?

Because the EFV restricts the flow of gas, it reduces the potential for explosions, fires, and personal injury. Installation of an EFV wonít protect against customer appliance malfunction, customer houseline gas leaks, small punctures in the underground pipe, or gas meter leaks. An EFV may not protect against damage to pipelines from earthquakes or flooding. It is also important to understand that an EFV does not shut off the flow of gas completely. Some leakage may still occur and result in a hazardous condition.

Where is an EFV installed?

An EFV is installed on the service pipeline that runs underground between the gas main (which is usually located in or near the street, alley, or easement) and the Oneonta Utilities gas meter on the customerís property.

Does my service already have an EFV?

Oneonta Utilities has installed EFVs on most new or replaced service pipelines installed after June, 2008.

How much does it cost to have an EFV installed?

If you do not already have an EFV installed and choose to have an EFV installed, you will be responsible for installation costs. Please call our Oneonta Utilities office for more information. If you choose to have an EFV installed, Oneonta Utilities will schedule the installation on a date that is mutually agreeable and provide details about the work that will be done. Installing an EFV involves excavation of the service pipeline. Natural gas service will be interrupted in order for the installation of the EFV to occur.

How can I prevent damage to pipelines?

Call 811 BEFORE you dig! 811 is a FREE service that gets utility-owned underground lines located and marked so you can safely dig. Be sure to call at least two working days before starting a project and always use hand tools when digging within 18 inches of the marked utility-owned underground line. Please visit Alabama 811 | ( for more details.