Gas flow is controlled only at the appliance where the problem exists.
1/2 Inch OD X 3/8 Inch ID, 1/2 Inch MIP x 1/2 Inch FIP 60 Inch SS Gas Connector W/ EFV Automatically Activate Automatically Reset No Battery needed 100% Performance Tested Applications: Dryers, Boilers, BBQ Grills, Ranges / Ovens, Furnaces, Fireplaces, Space Heaters, Tankless Water Heaters, Rooftop Units, Manufactured Homes. Automatic Excess Flow Shut-Off Connectors: In the case of a gas rupture or a disconnect from the appliance, TSC EFV detects increase of gas flow and immediately shut-off the supply of gas.