1. Install a pressure reduction valve on a nitrogen cylinder. (Fluorocarbon and carbon dioxide gases can cause condensation and oxygen causes an explosion).
2.Connect the pressure reducing valve to a meter and then to the tube on the gas side and liquid side of the external unit.
3. On the side of the indoor unit, plug all tubes on the gas side, except those of the indoor units that are to be washed.
4. Open the source valve on the nitrogen cylinder and increase the pressure on the secondary side of the nitrogen cylinder and increase the pressure on the secondary side of the pressure reducing valve until it reaches 0.5MPa (5kg / cm2G), and then open the valve on the meter connected to the gas side pipe.
5. Quick wash
Press the end of the gas pipe on the inside with the palm of your hand.
When the pressure is so high that you can no longer hold it against the end of the tube, remove your hand from the tube (This is the first wash). Press again with your hands.
Wash the tube a second time. (When washing, place a piece of gauze, etc. on the end of the tube and then check that there is no debris or moisture in the gauze. Repeat the washing process until nothing else comes out of the tube).
6. Close the pressure gauge valve, and repeat the above process on the next indoor unit (No. 2 to No. N). Close the meter valve, open the valve on the meter that is connected to the liquid side tube and allow the nitrogen to flow, and wash the liquid side tube.
