Montana-Dakota Home » Safety & Education » Excess Flow Valve


Excess Flow Valve (EFV)

An EFV is a safety device designed to automatically stop or restrict the flow of natural gas if an underground pipe is broken or severed. Such damage is usually the result of some type of excavation. Although an EFV may help limit the effects or damage of such an incident, the best way to protect against such incidents is to ensure that anyone excavating on your property has called 811 to have underground service lines properly marked before digging. Installation of an EFV will not protect against customer appliance gas leaks, small gas service line punctures or gas meter leaks. An EFV may not protect a pipeline from damage caused by flooding or earthquakes. EFVs are not available for some customers due to the amount of gas used, areas with delivery pressure less than 10 psi or other circumstances that hinder the effectiveness of the EFV.


EFV Location

The EFV is installed underground on the service line that runs between the gas main located in public right of way or a dedicated utility easement and the natural gas meter. Generally the EFV is installed as close as possible to the gas main. In some instances the location may need to be installed further from the gas main to accommodate interference from other buried structures.


EFV Installation Costs

If you would like to have an EFV installed in your service line, please contact Montana-Dakota at 800-638-3278. The installation is estimated to be $650, but the actual installation cost varies depending on the difficulty of the installation. The customer may be responsible for costs associated with installation, replacing or maintaining the EFV. Estimates for cost and timeframe for construction will be provided as requested on a case-by-case basis. The EFV will be installed at a time that is mutually agreeable to the company and customer. Since the EFV will be installed on Montana-Dakota’s  gas pipe, only Montana-Dakota or its approved contractors may perform the installation.

A printable document containing the information presented on this page is also available.