The nozzle is a restriction. To hold blasting pressure you must feed the volume that orifice wants. If CFM is short, PSI at the tip falls, cleaning slows and media is wasted. Tank litres on the compressor nameplate are not the same as continuous CFM.
Approximate free-air demand at the nozzle
| Nozzle | 80 PSI | 100 PSI | 120 PSI | Min screw size (guide) |
|---|---|---|---|---|
| 5 mm (#3) | 45 CFM | 54 CFM | 63 CFM | CKPM-15A class |
| 6.5 mm (#4) | 81 CFM | 94 CFM | 108 CFM | CKPM-30A class |
| 8 mm (#5) | 137 CFM | 161 CFM | 185 CFM | XLPM-60A class |
| 9.5 mm (#6) | 196 CFM | 230 CFM | 264 CFM | XLPM-60A / 75 class |
| 11 mm (#7) | 254 CFM | 300 CFM | 346 CFM | XLPM-75 / 100 class |
| 12.5 mm (#8) | 338 CFM | 396 CFM | 454 CFM | XLPM-100+ class |
BLAST APEX resells Boss rotary-screw compressors (CK 10-50 and XL 60-175) on one page. Size CFM to the nozzle with /guides/cfm-table. Add a receiver near the pot so the nozzle does not starve on long hose.
- Every 15 m of undersized hose costs a few PSI. Use 25 mm ID with 8 mm nozzles, 32 mm with 10 mm.
- A worn nozzle that is 1.5 mm oversize can jump CFM by about 30%.
- Fit a moisture separator. Hot high-CFM air dumps water into the pot and clumps slag.