This is a circular published in the interest of all our customers worldwide tocaution them that for production of medical/hospital oxygen from the oxygenplant, it is very necessary that the main equipment i.e. the air separation plant,where the actual separation/distillation of oxygen and nitrogen takes place fromair consisting of many trays should be made of cryogenic grade stainless steelcolumn with temperature as low as -190 degC below zero. This is extreme coldtemperature which is known as cryogenic temperature and ordinary materials likecopper, brass and ordinary steel the properties changed and there is a reactionbetween copper and oxygen and other impurities. These impurities are collectalongwith oxygen and carried to the cylinder. Therefore the following caution has been issued.
1. The medical grade oxygen for confirmingAmerican/European Pharmacopia has to be completelyfree from moisture, hydrocarbons and any form of oxidescarbonates, mono-carbonates including CO2 CO NH3 SO2CL2, CH4 etc. or dangerous chemical formations which maytake place in the air separation column with reaction ofcopper and ordinary steel or brass with oxygen, water andcarbon-dioxide etc.
2. To produce medical grade oxygen, it is most essential touse STAINLESS STEEL (Cryogenic grade) argon welded inthe manufacture of the air separation column, piping etc.specially the trays where the distillation/separation ofoxygen and nitrogen takes place. This will prevent any typeof chemical reaction as it is the safest and most strong andsturdy material used by American/Europeanmanufacturers
3. Completely avoid usage of old type of materials such ascopper, brass and ordinary steel used in manufacture of airseparation columns for oxygen/nitrogen plants.
4. It is cautioned by the American/European standards of thehazards of breathing oxygen contaminated by copper,brass and ordinary steel which can cause evendeath/serious injury to the person breathing oxygenproduced from old type of local Indian/Chinesemanufacturers who are not giving proper advice/warning to the customers.
The customer is advised to select the complete air separation columninside the cold box including all the trays, vessels and piping to be made ofspecial grade stainless steel .