Flow rates and pressures: https://raycut.co.za/parameters
Compressed air for thicker steel needs more flow. AG-AIR/SCREW-22: 22 kW, 380 V, 16 bar rotary screw, 2.1 m³/min, PMS VFD, touchscreen, 6-level filter, air dryer; suitable for fibre laser ≤12 kW. Same family as AG-AIR/SCREW-15 (15 kW, 1.2 m³/min, ≤6 kW fibre). One 22 kW unit uses less electricity and costs less than two 15 kW units Y-connected.
Oxygen: cylinder is still the practical method. Cylinder pressure about 100 bar; oxygen use is low so a cylinder lasts.
Nitrogen cylinder: high flow for cutting, so a cylinder typically lasts about 15 minutes.
A nitrogen generator (15 bar, 22 bar, or higher) plus booster, generator, and storage is a large custom system (around R2m at this date), not a stocked package.
Bulk / cryogenic nitrogen: supplier-refilled tanks, then pump/vaporizer; liquid nitrogen cannot be used directly; final pressure can reach 35 bar. Small liquid-nitrogen dewars meant for refrigeration are not pure enough for laser cutting.
