Laser cutting machine gas system pit avoidance guide（Selection·Air supply·pipeline·use·maintain）

This article covers oxygen/Nitrogen/air three cutting gases、Air supply method、Piping Specifications、Purity requirements、Common faults，Help you avoid all traps at once。

one、Cutting gas selection and pit avoidance guide

1. Three core uses of gases（Don't use it wrong）

✅ oxygen（O₂）：Designed for carbon steel cutting，Using oxidation reaction to assist cutting，fast、low cost。

✅ Nitrogen（N₂）：Dedicated to stainless steel/Aluminum plate cutting，No oxidation、Bright cut surface、No residue，Is a protective cut。

✅ compressed air：for thin sheets、roughing、Assisted perforation，Very low cost，But the cut surface is easily oxidized，Suitable for scenes where appearance requirements are not high。

Use wrong gas → Carbon steel cannot be cut with nitrogen、Stainless steel cut with oxygen turns black and is scrapped。

2. Purity requirements：If the purity is not enough, the cutting quality will be scrapped directly.

oxygen purity：≥99.5%（Carbon steel cutting），Low purity will lead to slag hanging、The cut surface turns black、Cutting speed is slow。

Nitrogen purity：≥99.99%（Stainless steel/aluminum），Low purity will cause the cut surface to turn yellow、Oxidation、Matte，Can't even cut through。

compressed air：Must be filtered to remove water and oil，Oil and water will contaminate the lens、Cut mouth，Cause abnormal cutting。

3. How to choose the air supply method？gas cylinder/liquid nitrogen/Nitrogen generator comparison

gas cylinder：Suitable for low power、small batch、temporary use，High cost、Frequent bottle changes are troublesome。

Dewar jar/liquid nitrogen：Suitable for medium power、continuous production，Stable air supply、Lower cost than gas cylinders。

Nitrogen generator/oxygen concentrator：Suitable for high power、24hourly continuous production，Lowest cost for long-term use，But equipment investment is high。

Gas cylinder for small power，High power must be installed on the nitrogen generator/liquid nitrogen，Otherwise, insufficient air supply will cause cutting interruption.。

two、Piping and installation pit avoidance

1. Pipe material must be stainless steel/copper pipe，It is strictly forbidden to use ordinary plastic pipes

Laser cutting gas pressure is high（Highest3MPa），Ordinary plastic pipes have insufficient pressure resistance、Easy to age and crack、Air leakage，even cause safety accidents。

recommend：304stainless steel pipe/Copper tube，Corrosion resistant、High voltage resistance、Long life。

2. Pipe diameter must match flow rate，If the air supply volume is small, the pressure will drop.

For low power machinesΦ8–Φ10pipeline；For medium powerΦ10–Φ12；For high powerΦ12–Φ16。

Pipe diameter is too small → The air pressure drops instantly during high-pressure cutting → Cut off the fire、Hanging residue、Can't cut through。

3. Multi-stage filtration must be installed：Remove water+Degreasing+Dust removal

compressed air/Nitrogen must pass through：pre-filter→freeze dryer→Precision filter（0.01μm）。

No filtering → water、Oil、Dust enters the laser head → contamination protection lenses → Power drop、Explosive gun、Laser damaged。

4. Piping must be leak-free，Air leakage will cause unstable air pressure

Must use soapy water after installation/Leak detector tests all joints、valve、pipeline。

Air leakage → air pressure fluctuations → Cutting quality is unstable、gas waste、Costs soar。

three、Avoid pitfalls in use and debugging

1. pressure/Flow rate must match power and plate thickness

Carbon steel oxygen cutting：pressure0.5–1.0MPa，Flow rate increases with thickness。

Stainless steel nitrogen cutting：pressure1.5–3.0MPa，High-power thick plates require higher pressure。

Not enough pressure → Can't cut through、Hanging residue；Pressure is too high → waste of gas、Cutting surface becomes wider。

2. Pipelines must be protected from freezing in winter，Otherwise it will freeze and block

Under low temperature environment，Residual moisture in pipes will freeze → clogged pipeline → No air output → Equipment downtime。

solve：Install heating tape、thermal insulation cotton，Or use a dryer to remove water completely。

3. It is strictly prohibited to mix gas pipelines，Prevent cross contamination

oxygen、Nitrogen、Air must be piped independently，Sharing is strictly prohibited，Otherwise, the gas purity will decrease、Cutting quality scrap。

Four、Maintenance and troubleshooting

1. Replace filter elements regularly，Otherwise it will be blocked

Pre-filter：1–2Monthly replacement；Precision filter element：3–6Monthly replacement；Dryer filter element：6–12Monthly replacement。

Do not replace → Filter element clogged → Insufficient traffic、Air pressure drops、Abnormal cutting。

2. Drainage regularly：gas tank/filter/dryer

Manual drainage every day，Otherwise, moisture will enter the pipes → freeze、corrosion、Contaminated lenses。

3. Common faults：Unstable air pressure、Cut off the fire、Hanging residue

reason：Air leakage in pipeline、Filter element clogged、Pipe diameter is too small、Gas purity is not enough。

solve：Leak detection、Replace filter element、Thick pipes、Improve gas purity。

five、Summary of pit avoidance of laser cutting machine gas system

1. gas：Oxygen for carbon steel，Stainless steel/Nitrogen for aluminum，Available air for thin plates。

2. purity：oxygen≥99.5%，Nitrogen≥99.99%，The air must be free of water and oil。

3. pipeline：Must useStainless steel/copper pipe，Pipe diameter matches flow rate，Disclosure is strictly prohibited。

4. filter：Multiple levels of filtration are required，Water, oil and dust removal，Protect laser head。

5. Air supply：Gas cylinder for small power，High power nitrogen generator/liquid nitrogen，Ensure continuous air supply。

6. maintain：Replace filter element regularly、drain、Antifreeze，Extend equipment life。

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