Nozzle & Compressor Sizing Calculator
Calculate CFM requirements, hose pressure loss, breathing air demand, and fuel burn.
Results are estimates based on industry-published data. Verify against manufacturer specs for your specific equipment.
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Data sources
- Nozzle CFM values: Clemco Industries & Kleenblast technical bulletins
- Pressure-flow relationship: Bernoulli principle (CFM scales with √P)
- Altitude derate: 3% per 1,000 ft — Atlas Copco, GPSA Section 13
- Breathing air: 15 CFM per blaster for Type CE hoods (OSHA 29 CFR 1910.134)
- Diesel fuel: 0.05 gal/CFM/hr at full load — industry field estimation method
- Compressor headroom: 25% safety margin per compressed air best practices
Common questions
What size compressor do I need for sandblasting?+
It depends on your nozzle size. A #5 nozzle at 100 PSI needs about 161 CFM, a #6 needs 232 CFM, and a #7 needs 315 CFM. Add 15 CFM per blaster for breathing air, derate for altitude, and add 25% headroom. Most single-nozzle jobs run on a 375 CFM compressor. Two-nozzle setups typically need 750-900 CFM.
How much CFM does a #6 blast nozzle use?+
A #6 (3/8") nozzle uses about 232 CFM at 100 PSI. At 150 PSI it draws about 284 CFM. The relationship is proportional to the square root of pressure — doubling pressure increases CFM by about 41%, not double.
How much does hose length affect blast pressure?+
Typical pressure loss is 0.5-3 PSI per 50 feet depending on hose inner diameter. A 1-1/4" ID hose loses about 0.8 PSI per 50 feet. Undersized hoses lose significantly more — a 3/4" hose loses about 3 PSI per 50 feet. Keep hoses as short and wide as practical.
How much diesel does a blast compressor burn?+
Roughly 0.05 gallons per CFM per hour at full load. A 375 CFM compressor burns about 19 gal/hr, and a 900 CFM rig burns about 45 gal/hr. Actual consumption varies with load factor — most jobs run at 60-80% load.
Does altitude affect compressor output?+
Yes. Compressors lose about 3% output per 1,000 feet of elevation. At 5,000 feet you need roughly 15% more compressor capacity than at sea level to get the same nozzle performance.
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