Dual Flow Plasma

(a) Dual flow plasma cutting.

Dual flow plasma cutting provides a secondary gas blanket around the arc plasma, as shown in figure 10-73.

The usual orifice gas is nitrogen. The shielding gas is selected for the material to be cut.

For mild steel, it may be carbon dioxide (CO2) or air; for stainless steals, CO2; and an argon-hydrogen mixture for aluminum.

For mild steel, cutting speeds are slightly faster than with conventional PAC, but the cut quality is not satisfactory for many applications.