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Air receiver tank size

Enter compressor capacity, pressure band and demand peaks to get the receiver volume that limits cycling and keeps minimum plant pressure.

Pre-sizing and estimating tool: results do not replace design, calculations or reports signed by a licensed professional, nor verification against the applicable codes and standards.

Pre-sizing
Compressor

Load/unload: up to one cycle every 30 s (120 per hour) on modern screw units. Start/stop: 6 to 15 starts per hour depending on the motor. VSD: size for the minimum speed range.

Demand peaks

Peaks such as blowers, blasting or machine starts exceeding compressor capacity for a few seconds. Enter zero if none.

—Recommended receiver volume
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Required volume versus pressure band

A narrower band needs more volume for the same number of cycles.

Tap the chart to see the values.

Pressure during the demand peak

Pressure decay in the chosen receiver while demand exceeds the compressor.

Tap the chart to see the values.

The report gathers this page's inputs, results, equations, assumptions and references, with fields for project, engineer and revision. In the print dialog, choose Save as PDF.

Method, assumptions and references

Equations used

Cycling: V = 0.25 · qc · p1 · T0 ÷ (fmax · Δp · T1) (qc in m³/s, p1 = 1.013 bar(a), fmax in cycles/s, T0 = 303 K in the receiver)
Peak: V = q_excess · t · p_atm ÷ (p_unload − p_min)
Volume conversion: 1 m³ = 264.17 gal; 1 m³/min = 35.31 cfm

Assumptions and limits

  • The 0.25 factor comes from the worst cycling case, with demand equal to half of compressor capacity.
  • Useful volume includes receiver and piping; large networks add storage.
  • VSD compressors need less volume; here only the range below minimum speed, about 25% of capacity, is considered.

Standards and technical documents

  • Atlas Copco: Compressed Air Manual, 9th ed., capítulo de dimensionamento de reservatórios
  • Compressed Air Challenge / U.S. DOE: Improving Compressed Air System Performance — Sourcebook
  • ISO 11011:2013: Compressed air — Energy efficiency — Assessment
  • EN 286-1 e EN 13445: recipientes a pressão simples e não submetidos a chama

U.S. regulations

  • OSHA 29 CFR 1910.169: air receivers
  • ASME BPVC Section VIII, Division 1, and National Board Inspection Code (state jurisdictions)

Frequently asked questions

What size air receiver do I need?

It depends on compressor capacity, pressure band and allowed cycles per hour. A common rule for load/unload compressors is 1 to 2 gallons per cfm; poorly controlled systems may need 3 to 5.

Does a bigger receiver save energy?

It does when it eliminates short cycling and lets the system run at a lower average pressure, and when it covers peaks without starting another compressor. Beyond what is needed, gains are small.

Which rules apply to air receivers?

Receivers are pressure vessels: ASME Section VIII construction and state jurisdiction rules, plus OSHA 1910.169 (drain, gauge and safety valve).