1. Before operation, check whether the sealant pad of the vacuum pump is damaged, and the vacuum gauge is reset to zero. Combine the fluorinated tube, vacuum gauge and vacuum pump.

2. Unscrew the nut at the fluorine filling port from the valve, and screw the fluorine filling pipe onto the fluorine filling port. Turn on the vacuum meter, and then turn on the vacuum pump power switch to start vacuuming. The vacuum degree of the normal system should be below - 756 mmHg (- 0.1 Mpa). The vacuum pumping time shall be determined according to the size of the refrigeration system and the size of the vacuum pump.

3. After the evacuation operation, close the three-way valve of the meter, slightly open the valves of the large and small pipes of the air conditioner to prevent air backflow, quickly remove the fluorine filling pipe and vacuum gauge, and fully open the valve again.