Abrasive Blasting, Shot Peening & Surface Prep worked example

Compressor Air Demand at 61% simultaneous nozzle duty factor: a worked example

This worked example runs the compressor air demand numbers for a tougher week than the baseline: 61% simultaneous nozzle duty factor instead of the typical 85%. Estimate effective compressor CFM demand from nozzle air volume, blast runtime, and simultaneous blasting load.

The inputs for this scenario

  • Total nozzle air consumed: 2,400 cfm-hr (held at the documented default)
  • Hours of active blasting: 8 hr (held at the documented default)
  • Simultaneous nozzle duty factor: 61 % (the input this scenario stresses; the baseline uses 85)

Working through the calculation

  • The calculation starts from the formula this tool documents: Raw demand = nozzle air volume รท blast runtime.
  • Effective compressor demand works out to 183 cfm at these inputs, and this is the headline figure for the scenario.
  • Raw nozzle demand works out to 300 cfm at these inputs.
  • Simultaneous nozzle load works out to 61 % at these inputs.
  • Blast runtime works out to 8 hr at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where simultaneous nozzle duty factor sits at 85% and the headline result is 255 cfm, this scenario comes in 28.24% below the baseline at 183 cfm.
  • Use it when specifying or renting a compressor for a blast job, or checking whether existing air will hold pressure across all nozzles. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Effective compressor demand: 183 cfm (headline result)
  • Raw nozzle demand: 300 cfm
  • Simultaneous nozzle load: 61 %
  • Blast runtime: 8 hr

Run it with your numbers

  • To rerun this with your own numbers, open the live Compressor Air Demand calculator, set simultaneous nozzle duty factor to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.