All gas pipes should be degreased, cleaned and packaged before piping installation of the medical oxygen system; they should be distinguished from ungreased pipes to prevent confusion. Specifically, the cleaning of the pipes can be carried out using the following six recommended cleaning methods.

1. Alkaline washing - in a solution made of 5 L of water and 100 g of industrial alkali cleaner (30 g/L) in hot water at about 82°C.

Wash, then, rinse thoroughly in cold water, then clean hot water, and allow to dry. The cleaning agent can be sodium triphosphate or tetraphosphate, sodium carbonate, sodium hydroxide, sodium metasilicate, or sodium orthosilicate, plus a wetting agent, or a combination of any of the above solutions.

2. Steam solvent cleaning - rinse with steam containing dry cleaning gasoline-type solvent or its equivalent, then rinse thoroughly with clean steam, and then rinse with hot air or dry air.

3. Steam Detergent Cleaning - Rinse with steam containing detergent followed by clean steam cleaning and hot or dry air Purge.

4. Steam cleaning - cleaning with clean steam and rinsing with hot or dry air.

5. Steam degreasing - using the method of "steam dipping" or "steam flushing", thoroughly clean with trichloroethylene or trichloroethane (methyl chloroform) solvent, and then rinse with dry air.

Note: When cleaning copper tubes with this method. Care should be taken that it is not harmful to the protection of operators and the environment. The cleaned copper pipes should be free of harmful residues.

6. Refrigerant degreasing - steam cleaning with refrigerant and purging with hot air and dry air.

After the tubing has been cleaned and dried, the ends should be capped, plugged or otherwise sealed immediately. In addition, another method can be used, that is, before the pipe is capped or plugged, dry and oil-free nitrogen gas is charged.