ENSTAR is required by federal regulation to install an Excess Flow Valve (EFV) in all new or renewed natural gas service lines that serve a single-family residence. An EFV is a safety device inside the service line that shuts off the flow of natural gas in the case of excess flow traveling through the line.

Such excess flow could be caused by a number of factors, including damage to the line due to excavation or natural disasters. EFVs come in a variety of load capacities, and are designed for a specific range of gas flow, with some tolerance for additional load. The gas flow at the time of installation is determined by the number and efficiency of gas-fired appliances inside the home, as provided by the customer. However, installing additional appliances without notifying ENSTAR could exceed the allotted load capacity for an already-installed EFV, shutting off the gas flow.

The cost of EFV installation is included in the charge for a new or renewed service line. Installation of an EFV will NOT protect against customer appliance gas leaks, small service line punctures or gas meter leaks. An EFV may not protect against damages caused by natural disasters.