EFV’s are small mechanical valves designed to shut off gas flow in a line if the flow exceeds a pre-determined limit. This means that if a line is accidentally cut or damaged the EFV will close and prevent an uncontrolled emission of fuel gas into the environment. The design is equipped with a bypass flow feature that allows the valve to reset once the line pressure on the downstream side of the valve equalizes. As a result, EFV’s are considered a vital safety component of any gas distribution system, and are now required for virtually all gas service installations in the United States.
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