Various plasma cutters will require differing air pressures depending on the thickness of the metal you wish to cut. Plasma cutters need compressed air.  Your plasma cutter air pressure table or chart will indicate the precise setting for the air pressure.

How much air pressure does your plasma cutter need? Generally, Plasma cutters use air pressure in a range from 4 to 8 SCFM at 90 to 120 PSI. 

SCGM

First off, what is SCGM? This means “Standard Cubic Feet per Minute” and defines the flow of gas or air through a compressor. This procedure allows the electric power that will pump the air into an energy source as pressurized air, then evolving into kinetic energy which will expel air or gas.

SCGM is the speed of gas or airflow through the compressor at standard pressure conditions and temperature. The standard temperature used in calculating SCFM is in the range of 60° to 68° Fahrenheit with a 14.7 PSI pressure and humidity measuring 36%. These are “ideal” conditions of measurement. If you reside however in a place with a higher altitude, the temperature or level of humidity, compressor output will fall. “S” signifies standard and implies 68°F at sea level with 0% humidity. If you can’t evaluate your location conditions, add 50% to compressor capability or if your cutter requires 6CFM, get a compressor for 8CFM.

PSI

PSI signifies “Pounds per Square Inch” and this is the unit that measures exactly how much pressure will be placed on a space measuring a square inch. When referring to an air compressor, it indicates how much pressure the air compressor can produce.

Plasma Cutter Necessities

The arc used, which is super-heated itself will heat the system’s compressed air to the point where it evolves into plasma. Usually, a beginning or starting arc is needed to be able to generate plasma. The standard requirement of 4 to 8 SCFM at 90 to 120 PSI is the average needed to cut steel with a thickness of 3/8 to 7/8 inches.

While the plasma cutter will provide the compressed gas or air, it does require two other components that are fundamental to its success. An air-drying unit or filtering unit and of course, an air compressor. While the compressor delivers the air, moisture or contamination of air can interfere with your plasma cutter’s performance. Hence a drying/filtering system is essential.

Air Quality

The quality of the air used by a plasma cutter system is crucial to performance. Any type of moisture or oi particles trapped in the system will adversely influence the cut quality. Dust is likewise a major concern.

Plasma Cutter Air Pressure Examples

These examples will help you in determining and setting the correct air pressure for your plasma cutting system.

Conclusion

Depending on the size of your plasma cutter and the thickness of the metal you wish to cut, the above chart will help you select the correct air pressure for your plasma cutter.

Remember that the air used in the plasma cutter must be free of dust, contaminants, and moisture for top-quality performance.