Assist Gas Guide
Nitrogen vs Oxygen Laser Cutting: Assist Gas Choice and PSA Nitrogen Sizing
Oxygen assist gives carbon steel its fastest exothermic cut; nitrogen delivers bright, oxide-free edges on stainless steel and aluminum — and an on-site PSA generator (99.9% purity, 10-80 m³/h, 0.6-0.8 MPa) typically pays back in 6-12 months versus bottled nitrogen.
Nitrogen vs Oxygen: What Each Gas Actually Does
Cutting mechanism and edge behavior are general engineering reference; purity, flow and payback data are stated on the product page.
| Aspect | Oxygen (O2) | Nitrogen (N2) |
|---|---|---|
| Best suited to | Carbon steel | Stainless steel, aluminum |
| Mechanism | Oxidation adds heat to the cut | Inert jet blows molten metal without burning |
| Edge result | Oxide layer typical on the cut edge | Bright oxide-free edge with high-purity N2 |
| Cost behavior | Lower unit gas cost | The main recurring gas cost in N2 cutting |
Practical consequence: fabricators cutting significant stainless or aluminum volume face nitrogen as their largest recurring gas expense — which is the problem on-site generation addresses.
PSA Nitrogen Generator: the Verified Specification
Produces 99.9% pure nitrogen from compressed air, adjustable flow 10-80 m³/h at 0.6-0.8 MPa inlet pressure, matched to fiber laser cutting machines from 1000W to 12000W. Dual filtration stages plus membrane separation remove moisture and particulates; automatic pressure regulation holds flow during peak cutting cycles. Runs below 75 dB, CE certified; routine maintenance is monthly filter cartridge replacement.
Sizing Logic
- 1
Estimate the N2 share of your mix
Stainless/aluminum-heavy shops run nitrogen as the primary assist gas; carbon-steel-dominant shops cut with oxygen and size N2 for stainless jobs.
- 2
Match flow to machine power
10-80 m³/h covers 1000W-12000W machines; peak assist-gas demand on thick stainless is where bottle regulators fall short.
- 3
Purity
99.9% stated as standard for fiber laser cutting of stainless and aluminum; higher-purity configurations (e.g. 99.999%) available on request.
- 4
Air supply
Compressed air at 0.6-0.8 MPa; Xinhong's screw air compressor (1.3-3.5 m³/min, 0.7-1.3 MPa, oil-free clean air with integrated dryer) is the matched upstream unit.
- 5
Gas routing
Gas mixing system adds programmable 3-gas (O2/N2/air) recipe switching with ±1% flow accuracy and consumption monitoring.
The Economics, as Stated
Compared with bottled nitrogen, stated typical payback of 6-12 months depending on consumption volume and local bottled gas pricing; after payback, running cost reduces to compressor electricity and monthly filters.
Typical Applications
Typical application examples.
- Commercial kitchen equipment (nitrogen-assist oxide-free food-grade edges on stainless sinks)
- Automotive suppliers
- Stainless steel fabrication
- Aluminum processing
- Aerospace components
- Decorative metal fabrication
- Contract laser cutting facilities
Frequently Asked Questions
Is 99.9% purity sufficient?
Stated as the standard for fiber laser cutting of stainless steel and aluminum, producing bright oxide-free edges; ultra-high-purity (99.999%) PSA configurations available on request.
What air compressor does a PSA generator need?
Supply at 0.6-0.8 MPa inlet pressure; required capacity depends on the flow setting — provide machine power and daily usage for correct sizing.
How is gas flow matched to the machine?
Adjustable 10-80 m³/h with automatic pressure regulation during peak cycles, sized to the machine's power tier.
What maintenance does PSA generation involve?
Monthly filter cartridge replacement is the primary task; carbon molecular sieve beds stated to last 5+ years under normal conditions, no daily maintenance.
What determines the payback period?
Nitrogen consumption volume and local bottled gas price — stated typical window 6-12 months.
Request a Flow-Rate Specification
Tell us your machine power and stainless share for a flow-rate specification.
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