Industrial oxygen grades and purity
Oxygen (O₂) is not a fuel — it is what makes fuels burn hotter and faster. In an oxy-acetylene flame it takes the temperature to around 3,100 °C, far beyond anything achievable in air, which is what makes oxy-fuel cutting and welding possible at all.
IIGAS supplies industrial oxygen against IS: 309 (2005, 4th revision), with higher-purity grades where the process requires them. Medical oxygen is a separate product manufactured to Indian Pharmacopoeia — it is not the same thing as industrial oxygen and the two must never be substituted for one another.
| Grade | Typical purity | Where it is used |
|---|---|---|
| Industrial oxygen (IS 309) | 99.5%+ | Oxy-fuel cutting and welding, brazing, general industrial use |
| High-purity oxygen | 99.9%+ | Glass working, furnace enrichment, laboratory and process use |
| Cutting oxygen | 99.5%+, high flow | Flame cutting, gouging and scarfing — flow rate matters as much as purity |
| Medical oxygen (IP) | To Indian Pharmacopoeia | Clinical use only — a separate product line, see our medical oxygen page |
Cut quality in flame cutting is unusually sensitive to oxygen purity. A drop of even a fraction of a percent slows the cutting rate and roughens the cut edge measurably — which is why cutting oxygen is worth buying on specification rather than on price alone.
What industrial oxygen is used for
- ✓Oxy-acetylene and oxy-fuel cutting, gouging and scarfing
- ✓Oxy-acetylene welding, brazing and hardfacing
- ✓Steelmaking — decarburisation, lancing and furnace enrichment
- ✓Glass melting and lampworking, where oxy-fuel gives a hotter, cleaner flame
- ✓Non-ferrous smelting and foundry furnace enrichment
- ✓Effluent and wastewater treatment — oxygen enrichment of aeration
- ✓Aquaculture and fish farming
- ✓Chemical process oxidation and pulp bleaching
How oxygen is supplied
| Packaging | Typical content | Suits |
|---|---|---|
| 47 L high-pressure cylinder | ~7 m³ at 150 kg/cm² | Fabrication shops, site cutting, maintenance work |
| Cylinder bank / quad | Multiples of cylinder content | Production cutting, multi-torch shops, furnace work |
| Manifolded bank with changeover panel | Continuous | Cutting lines and processes that cannot stop for a cylinder change |
| On-site PSA oxygen plant | Continuous, generated on site | High steady consumption — typically 93–95% purity, suitable for cutting and most industrial duty |
| Cylinder-filling station | As required | Customers filling and distributing their own oxygen cylinders |
PSA oxygen typically delivers 93–95% purity. That is entirely adequate for most industrial duty including flame cutting, but not for applications specified at 99.5%+ — so the choice between cylinders and on-site generation depends on what your process actually requires. We will run that comparison honestly, including when it means we sell you a plant rather than gas.
Oxygen safety: the hazard people underestimate
Oxygen does not burn. It makes everything else burn — faster, hotter, and at temperatures that would not normally ignite. That distinction is what makes oxygen hazards counter-intuitive and why they are so often mishandled.
The classic incident is oil or grease on a regulator, valve or fitting. Under high-pressure oxygen, hydrocarbon contamination can ignite spontaneously and burn ferociously — no spark, no flame, no obvious cause. This is the single most important rule in oxygen handling, and it is broken routinely by people using the same hands, gloves or rags they have just used on machinery.
- ✓Never allow oil, grease or any hydrocarbon near oxygen cylinders, valves, regulators or fittings — including on hands, gloves and rags
- ✓Never use oxygen to blow down clothing, to ventilate a space, or as a substitute for compressed air; oxygen-enriched clothing ignites readily
- ✓Open cylinder valves slowly — rapid pressurisation of a regulator generates adiabatic heat
- ✓Fit flashback arrestors and non-return valves on both oxygen and fuel gas lines, at regulator and torch
- ✓Store oxygen cylinders separated from fuel-gas cylinders and away from combustible material
- ✓Use only regulators, hoses and fittings designated for oxygen service, and never interchange them with fuel-gas equipment
- ✓Ventilate enclosed spaces — oxygen enrichment above normal atmospheric levels is a serious fire hazard
Cylinder identification
Under IS 4379, industrial oxygen cylinders are black with no neck band, marked with the gas name and formula. Note carefully that carbon dioxide cylinders are also black, distinguished by a white neck band — on a mixed site, always read the label as well as the colour. Medical oxygen cylinders follow IS 3933, a separate identification standard.
Why buy oxygen from IIGAS
IIGAS has manufactured and supplied industrial gases since 1947 and sits on the BIS committees CHD 6 (Industrial Gases) and MED 16 (Gas Cylinders) — we manufacture to the standards those committees set.
We are also plant builders. We design and install PSA oxygen plants and oxygen cylinder-filling stations, and we supply the flashback arrestors and safety equipment that oxy-fuel work requires. If your consumption has reached the point where generating on site costs less than buying cylinders, we will tell you, and we can build it.
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