Locate the Valve: First, find the gas valve. It should be near the gas appliance or line you want to activate. Handle Position: Look for the yellow handle on the valve. The yellow color indicates that it’s part of a gas line. Make sure the handle is perpendicular to the pipe (in line with the pipe) to turn the valve on. If it’s parallel to the pipe, the valve is off. Turn the Handle: Rotate the handle 90 degrees (quarter-turn) from the closed position to the open position. This allows gas to flow through the valve.