The Oxygen Cleaning Standards

“Oxygen cleaning” is effectively a very thorough cleaning operation of your storage and distribution systems that carry oxygen >22%. The intent is to remove all traces of products that could either cause, facilitate or feed a fire.
After chemical cleaning, the equipment is often dried to -40 o C dew-point before the system can be put into service.

No. There are various chemicals that can be used to achieve the cleanliness required. Their selection will be determined by the material(s) of your equipment, and the type / severity of any contamination. These are typically mild degreasers/cleaners.

There are various methods of inspection.

The simplest inspection is “Visual inspection” under white light and/or UV light. Many oils/hydrocarbons will fluoresce beneath an ultra-violet light, so contamination that wasn’t necessarily visible under the white light, can often be identified with UV.

This can be supplemented with a “swab test”. A white, lint-free cloth wetted with a suitable solvent is lightly wiped over the surface and inspected for discolouration.

Finally, a quantitative test – the “Solvent Extraction” test can be used. A measured volume of solvent is poured over a cleaned surface, collected, then analysed in a laboratory to determine the extent of any contamination it picked up. There are recommended limits - usually dependent on the oxygen % being stored.