Air Receiver Tank Size Calculator
An air receiver stores compressed air so the compressor runs fewer load and unload cycles and short peaks do not drop the line pressure. Enter your compressor's output to get the receiver size, or size it for a known peak.
Two ways to size an air receiver
1. Rule of thumb. Allow 3–5 US gallons of receiver per CFM of compressor output, about 11–19 litres per CFM (Compressed Air Best Practices). Very steady demand can use about 2 gallons per CFM; plants with large swings in demand are better served by 5–10 gallons per CFM (Plant Services, citing Compressed Air Challenge guidance).
2. Storage for a known peak. When a short, heavy demand exceeds what the compressor supplies, size the receiver to cover the gap while pressure falls to the lowest level your machines accept:
This is the formula EXAIR gives from Compressed Air Challenge training. Example: a 40 CFM shortfall (1,133 litres/min) for 60 seconds, with pressure allowed to fall from 8 to 6.5 bar, needs 1 × 1,133 × 1.013 ÷ 1.5 ≈ 765 litres.
Receiver sizes for Karan screw compressors
| Model | CFM at 8 kg/cm² | Receiver (litres) |
|---|---|---|
| KCS-05 | 19 | 220–360 |
| KCS-7.5 | 29 | 330–550 |
| KCS-10 | 39 | 440–740 |
| KCS-15 | 59 | 670–1,120 |
| KCS-20 | 80 | 910–1,510 |
| KCS-25 | 108 | 1,230–2,040 |
| KCS-30 | 129 | 1,460–2,440 |
| KCS-40 | 164 | 1,860–3,100 |
| KCS-50 | 222 | 2,520–4,200 |
| KCS-60 | 286 | 3,250–5,410 |
| KCS-75 | 357 | 4,050–6,760 |
| KCS-100 | 464 | 5,270–8,780 |
| KCS-150 | 724 | 8,220–13,700 |
Fitting and safety
- Air enters at the bottom of the receiver and leaves at the top, with a drain at the lowest point (ELGi installation guide).
- Fit a safety valve, a pressure gauge and an automatic or manual condensate drain.
- Ask the supplier for the design pressure, the hydro-test certificate and the safety-valve setting before you install.
Frequently Asked Questions
Straight answers from our engineers, last reviewed October 2026. Click a question to see the answer.
Ask our engineers01How big should my air receiver tank be?
Allow about 3–5 US gallons per CFM of compressor output, roughly 11–19 litres per CFM (Compressed Air Best Practices). For Karan Micro Industries' 20 HP KCS-20 at 80 CFM that is about 910–1,510 litres. Very steady demand can use less; plants with large swings in demand should use more.
02What is the formula for air receiver sizing?
V = T × (C − R) × Pa ÷ (P1 − P2): T is the length of the peak in minutes, C − R the demand above what the compressor supplies, Pa atmospheric pressure (1.013 bar), and P1 − P2 the pressure fall you can accept. It is the formula EXAIR gives from Compressed Air Challenge training.
03What size receiver comes with a Karan reciprocating compressor?
Karan Micro Industries supplies its two-stage reciprocating compressors with receivers from 160 litres on the 3 HP KC 734 to 500 litres on the 15 HP models and above, fabricated in its Ahmedabad plant. For screw compressors the receiver is sized to your demand and quoted with the machine.
04Does Karan make air receivers?
Yes. Karan Micro Industries fabricates air receiver tanks in its own Ahmedabad plant and supplies them with its compressors, dryers and line filters. Send your compressor's CFM, working pressure and demand pattern for a receiver quote.