Converters and engineering calculators for industrial compressed-air systems.
Compressed air toolbox
Pressure
Pa, kPa, bar, psi, atm — absolute and gauge.
Results
- Pascals (Pa)
- — Pa
- Kilopascals (kPa)
- — kPa
- Kilopascals gauge (kPag)
- — kPag
- Megapascals (MPa)
- — MPa
- Bar
- — bar
- Bar gauge (barg)
- — barg
- PSI gauge (psig)
- — psig
- PSI absolute (psia)
- — psia
- Atmospheres (atm)
- — atm
Flow
m³/s, m³/min, m³/h, L/s, CFM, GPM.
Results
- Cubic meters / second (m³/s)
- — m³/s
- Cubic meters / minute (m³/min)
- — m³/min
- Cubic meters / hour (m³/h)
- — m³/h
- Liters / second (L/s)
- — L/s
- Cubic feet / minute (CFM)
- — CFM
- Gallons / minute (GPM)
- — GPM
Power
W, kW, HP, BTU/h.
Results
- Watts (W)
- — W
- Kilowatts (kW)
- — kW
- Horsepower (HP)
- — HP
- BTU / hour
- — BTU/h
Temperature
°C, °F, K.
Results
- Celsius (°C)
- — °C
- Fahrenheit (°F)
- — °F
- Kelvin (K)
- — K
Volume
m³, L, mL, ft³, gallons.
Results
- Cubic meters (m³)
- — m³
- Liters (L)
- — L
- Milliliters (mL)
- — mL
- Cubic feet (ft³)
- — pi³
- Gallons (gal)
- — gal
Weight
kg, g, lb, oz, tons.
Results
- Kilograms (kg)
- — kg
- Grams (g)
- — g
- Pounds (lb)
- — lb
- Ounces (oz)
- — oz
- Metric tons (t)
- — t
Length
m, cm, mm, yards, feet, inches.
Results
- Meters (m)
- — m
- Centimeters (cm)
- — cm
- Millimeters (mm)
- — mm
- Yards (yd)
- — vg
- Feet (ft)
- — pi
- Inches (in)
- — po
Standardised flow
SCFM (CAGI), ACFM (ISO 1217), Nm³/h, Nm³/min, DIN 1343 — with P/T/RH conditions.
| Flow | Unit | Pressure | Temp (°C) | RH (%) | SCFM | ACFM | Nm³/h | Nm³/min |
|---|---|---|---|---|---|---|---|---|
| | — | — | — | — | ||||
| | — | — | — | — | ||||
| | — | — | — | — | ||||
| | — | — | — | — |
SCFM = CAGI/ISO 1217 (1 bar abs, 20 °C). For standardised units the conditions are set automatically; only ACFM (actual conditions) is editable.
Total system volume
Cumulative internal volume: piping + receivers (2:1 elliptical heads).
Piping
| # | Inner dia. | Length | m³ | ft³ | gal |
|---|---|---|---|---|---|
| 1 | — | — | — | ||
| 2 | — | — | — | ||
| 3 | — | — | — | ||
| 4 | — | — | — |
Receivers
| # | Diameter | Length | Manual volume | m³ | ft³ | gal |
|---|---|---|---|---|---|---|
| 1 | — | — | — | |||
| 2 | — | — | — | |||
| 3 | — | — | — | |||
| 4 | — | — | — | |||
| Total volume | — | — | — | |||
Receivers: cylinder + 2:1 elliptical heads, rounded to the nearest standard size; a manual volume takes precedence when entered.
Pressure loss
Pipe pressure drop (Darcy–Weisbach, Swamee–Jain friction).
Pressure loss
- bar
- —bar
- kPa
- —kPa
Calculation details
- Friction factor
- —
- Velocity
- —ft/s
- Diameter
- —mm · —in
- Length
- —m · —ft
Darcy–Weisbach, air properties @ 20 °C / 1 bar abs (ISO 1217).
Pipe sizing
Recommended pipe diameter by pressure drop and velocity (open/closed loop).
Open loop — pressure drop
| Pipe | Velocity | ΔP | |
|---|---|---|---|
| Under | — | — | — |
| Optimal | — | — | — |
| Over | — | — | — |
Open loop — velocity (≤ 35 ft/s)
| Pipe | Velocity | ΔP | |
|---|---|---|---|
| Under | — | — | — |
| Optimal | — | — | — |
| Over | — | — | — |
Closed loop — pressure drop
| Pipe | Velocity | ΔP | |
|---|---|---|---|
| Under | — | — | — |
| Optimal | — | — | — |
| Over | — | — | — |
Closed loop — velocity (≤ 35 ft/s)
| Pipe | Velocity | ΔP | |
|---|---|---|---|
| Under | — | — | — |
| Optimal | — | — | — |
| Over | — | — | — |
Closed loop: Q/2 over L/2 (air reaches the critical point from both sides). Velocity red if > 35 ft/s; ΔP red if above the limit.
Receiver storage
Volume required to ride through a demand event without dropping below the minimum pressure.
Required receiver volume
- Cubic feet
- —ft³
- Cubic meters
- —m³
SCFM reference = 1 bar abs (CAGI / ISO 1217). V = (Q · t · P_atm) / (60 · ΔP).
Compressor sizing
Required ACFM capacity for site altitude, temperature and humidity.
Scenario 1
Required capacity
- ACFM (min conditions)
- —ACFM
- ACFM (max conditions)
- —ACFM
Scenario 2
Required capacity
- ACFM (min conditions)
- —ACFM
- ACFM (max conditions)
- —ACFM
CAGI / ISO 1217 correction (Annex C). Recommended = worst case (max conditions).
Flow test
Compressor flow from a load/unload test (isothermal compression in a receiver).
Result
- Total volume
- —ft³
- ΔP
- —psig
- Time
- —s
Isothermal compression: SCFM = (V · ΔP_abs · 60) / (P_std · t). P_std = 14.5 psia (1 bar abs).
Metered recovery
Receiver sizing and recovery validation across demand cycles.
Scenario 1 — required
Result
- Net demand
- —SCFM
- ft³ · L
- —ft³ · —L
- Recovery time
- —s · —min
Scenario 2 — adjustable
Result
- Net demand
- —SCFM
- Recovery time
- —s
Pressure cycle (4 cycles)
Volume = (Q_net · t · P_atm) / (60 · ΔP). Scenario 2 validates both volume AND recovery time.
Water removal
Water condensed at the aftercooler and dryer for given inlet/outlet conditions.
System analysis
- Inlet moisture
- —g/kg
- Aftercooler outlet temp
- —°C
- After aftercooler
- —g/kg
- After dryer
- —g/kg
- Dry-air flow
- —kg/h
Water removed (hourly)
- Aftercooler
- —L/h
- Dryer
- —L/h
Remaining water
- Remaining water
- —L/h
Magnus-Tetens psychrometrics. CTD: +25 °F (air) / +10 °F (water).
Indicative estimates — validate all results before any engineering decision.