NTSB Press Release

National Transportation Safety Board
Office of Public Affairs


December 8, 2006

Washington, DC - National Transportation Safety Board Chairman Mark Rosenker today welcomed Congress' passage of legislation mandating the installation of excess flow valves (EFVs) on natural gas pipelines serving single family residential housing. EFVs are designed to respond to an excessive flow of gas - due to a leak or rupture in a service line - by automatically closing and restricting the gas flow, thereby reducing the likelihood of an explosion and fire. The valves typically are installed at the connection of a service line to a mainline pipe.

"Excess flow valves are an effective way to save lives and protect property," said Rosenker. "I congratulate the members of Congress for taking a step that will provide significant safety benefits to a great many households."

The NTSB first addressed the need for standards for safety valves that could rapidly shutdown failed pipelines thirty-five years ago, focusing initially on service lines to schools and other public buildings in which large numbers of people gathered. As EFVs became cheaper and more widely available, the Board began advocating their use on residential service lines.

Current rules, dating from 1998, require natural gas distributors to either install EFVs on new or replaced single residence service lines or inform customers of their availability and install them if the customer agrees to cover the costs. However, the Board has been concerned that homeowners may not fully understand the safety benefits that EFVs can provide when they are faced with a decision that may require that they pay for the installation and maintenance of the device.

Today's action by the Congress makes installation of EFVs mandatory in all new and renewed single-residence gas service lines, unless operating conditions are incompatible with readily available valves. Many distributors are already in the process of installing the valves.

Noting the progress that has been made, Rosenker said he hoped to see expanded usage of the safety valves. "Our investigations of accidents over the years," he said, "clearly show that multiple-family residences and commercial establishments also would benefit from the protections afforded by EFVs."

NTSB accident reports and safety recommendations can be found on the Board's web site at www.ntsb.gov.

NTSB Office of Public Affairs: (202) 314-6100



The National Transportation Safety Board (NTSB) is an independent federal agency charged with determining the probable cause
of transportation accidents, promoting transportation safety, and assisting victims of transportation accidents and their families.