CalcPanel

Pneumatic Circuit Calculator #

Calculate cycle-average standard air demand for up to four cylinder groups, plus a user-defined simultaneous-use scenario. The page does not infer instantaneous actuator peak flow or automatically select compressor, valve, or FRL hardware.

Quick Calculator: Circuit Configuration

Enter a value supported by the machine sequence or measured demand profile

Cylinder Groups

0 = single-acting

Advanced calculator

Add Groups 2–4 for multi-size cylinder banks. Group 1 stays in Quick calculator.

About This Calculator

This planning screen calculates extend and, when rod diameter is nonzero, retract chamber volume; it converts cylinder volume to standard flow using absolute pressure and temperature. The undiscounted result assumes every active cylinder sustains its entered cycles/min. The scenario result applies only the factor you enter and must not be called instantaneous peak flow. Valve/FRL sizing requires stroke time, allowable pressure drop, Cv/Kv curves, tubing and exhaust losses; compressor selection also needs leakage, storage, controls and OEM FAD. Worked example: use the default groups to see both undiscounted and factored cycle-average demand. Browse all pneumatic calculators.

Results

Total Active Cylinders
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Undiscounted Cycle-Average FAD
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User-Factored Demand Scenario
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Compressor Verification
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Valve Verification
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FRL Verification
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Combined Swept Volume
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Continue Your Calculation

After total circuit demand, size the compressor or calculate pipe pressure drop for your distribution system.

Size compressor →

Input and Scope Checklist #

Use actual bore, stroke, rod diameter, operating pressure at the cylinder, supply temperature, count, and sustained cycles per minute. A rod value of zero intentionally models one supplied chamber per cycle; enter a nonzero rod for double-acting extend-plus-retract consumption. Cylinder force, buckling, cushioning, load dynamics, dead volume, tubing fill, leakage, and exhaust behavior are outside this calculation.

Circuit Demand Formulas #

Cylinder Air Consumption

V_extend = pi/4 x D^2 x S

V_retract = pi/4 x (D^2 - d^2) x S (double-acting)

FAD = (V_ext + V_ret) x cycles/min x (P_gauge + 14.7) / 14.7 / 1728

Total Circuit Demand

Undiscounted cycle-average FAD = sum of all active group FAD values

User scenario FAD = undiscounted FAD × entered simultaneous-use factor

Assumptions and Limitations

This is a planning-level cycle-average estimator. It does not model transient effects, acceleration/deceleration, valve coefficients, tubing fill, exhaust restriction, pressure dynamics, or receiver response. Do not use its factored result as instantaneous peak flow. Add leakage, reserve, growth, and redundancy only from documented project assumptions and verify package FAD and component flow curves.

Required Follow-Up Calculations #

Use Pneumatic Valve Cv with actuator stroke-time peak flow and allowable valve loss; verify FRL flow and pressure-drop curves with the manufacturer; use Air Compressor Sizing with justified leakage, growth, control and storage assumptions. Confirm the sequence against PLC timing or measured flow before treating a simultaneous-use factor as a design input.

Frequently Asked Questions #

How do you calculate total air demand for a pneumatic circuit?

Calculate extend and applicable retract chamber volume for each active cylinder, multiply by cycles per minute and count, then convert operating volume to the stated standard condition with absolute pressure and temperature. Sum groups for undiscounted cycle-average FAD; apply a simultaneous factor only as a separately justified scenario.

How do you size a valve for multiple cylinders?

Cycle-average SCFM is insufficient. Determine instantaneous flow from required stroke time and chamber fill, identify upstream and downstream absolute pressures, calculate required Cv/Kv, and verify the candidate valve’s manufacturer flow method, pressure loss, porting, exhaust path, and response.

What simultaneous use factor should I use?

Use a factor derived from the machine sequence, PLC timing, production states, or measured demand profile. If the evidence is unavailable, calculate explicit credible operating cases—including factor 1.0 where simultaneous cycling is possible—instead of assuming a generic average.