CGA G-4.1:2018

This publication describes the cleaning methods and requirements for equipment used in the production, storage, distribution, and use of liquid and gaseous oxygen to reduce the risk of fire, explosion, or promotion of combustion. Cleaning in accordance with this publication is required for all surfaces in contact with a gas or liquid that has an oxygen concentration greater than 23.5%. Examples of such equipment include station-ary storage tanks, road tankers, and rail cars; pressure vessels such as heat exchangers and distillation columns; compressors and pumps; and associated piping, valves, and instrumentation. However, the cleaning methods and requirements are not limited to this equipment. With modifications, these methods may be used for cleaning other oxygen and oxidizer (e.g., fluorine, nitrogen trifluoride, nitrous oxide) service equipment such as cylinders, cylinder valves, cylinder regulators, welding torches, and pipelines where regulatory re-quirements do not specify cleaning methods.
This publication does not replace or supersede any regulatory cleaning requirements specified by a national authority. For example, U.S. Department of Transportation (DOT) aluminum alloy oxygen cylinders shall be cleaned to the requirements of the Title 49 of the U.S. Code of Federal Regulations (49 CFR) Part 173.302(b)(3).