The following steps need to be followed to connect the gas line of the CNC plasma cutting machine:

1. Inspection and preparation. Make sure that the power cord, gas source cord, and spark cord of the CNC plasma cutting machine are normal and comply with the standards.

2. Connect the power cord. Connect the CNC plasma cutting machine's power cord to an AC power source, usually to a three-phase power source. You can use a wire clamp or plug to connect the power cord to ensure that the power supply meets the standards required by the cutting machine.

3. Connect the air source line. Connect the air source line of the CNC plasma cutting machine to air source equipment such as an air compressor or nitrogen bottle. Usually use a quick connector to connect the gas source line, and ensure that the gas pressure output by the gas source device meets the requirements of the cutting machine.

4. Connect the spark wire. The spark wire can be connected to the cutting machine through a plug or clip. Make sure the spark wire interface and plug are connected correctly.

In addition, before connecting the air source pipe interface, you need to confirm that there is no debris in the air source pipe and clean the air source pipe. Insert the air source pipe into the air source pipe interface of the CNC plasma cutting machine and ensure that the connection is reliable. Then connect the other end of the air supply pipe to the high-pressure air supply device. Make sure all connections are tight and there are no errors. Turn on the switch to start cutting.