CALCULATORS / PNEUMATICS, HYDRAULICS AND VACUUM

Compressed-air receiver sizing calculator

Isothermal receiver drawdown supplying constant reference-volume flow.

pneumatics-air-receiver.napkin / editable

SCENARIO COMPARISON

Compare the numbers.

This source describes an analytical model. Its quantities and checks are the view.

Scenario	availableAirL	durations
	100	60
	80	48

All calculated quantities are listed with the inputs. Switch to Source to inspect the equations.

SCENARIOS / CALCULATED VALUESSAME SOURCE

Change an input to see the consequences.

reserve time target60.00 s✓ passes

BASELINE INPUTS

volume50 LhighPressure800 kPalowPressure600 kPareferencePressure100 kPareferenceFlow100 L/min

CALCULATED

availableAir100 L

duration60 s

Edits change the baseline source.

THE SOURCE

Edits below update the same model.

# Compressed-air receiver sizing
# Scope: Isothermal receiver drawdown supplying constant reference-volume flow.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

volume = 50 L
highPressure = 800 kPa
lowPressure = 600 kPa
referencePressure = 100 kPa
referenceFlow = 100 L/min

availableAir := volume*(highPressure-lowPressure)/referencePressure [L]
duration := availableAir/referenceFlow [s]

check reserve time target: duration >= 30 s

scenario alternative: volume = 40 L

Calculated from your source · not saved

Baseline · Baseline

reserve time target60.00 s ✓ passes

alternative · alternative

reserve time target48.00 s ✓ passes

Illustrative first-order example. Checks are editable requirements, not design standards. The broader topic may require additional equations, data, and validation.

Formula and units

This example uses the following equations. Input names and units match the editable source above.

available air: availableAir = volume*(highPressure-lowPressure)/referencePressure [L]
duration: duration = availableAir/referenceFlow [s]

Original worked example

These are the baseline values in the downloadable source. Edits above let you test your own values.

Given

volume: 50 L
high pressure: 800 kPa
low pressure: 600 kPa
reference pressure: 100 kPa
reference flow: 100 L/min

Calculated

available air: 100 L
duration: 60 s

Assumptions and limits

Isothermal receiver drawdown supplying constant reference-volume flow.

The requirement checks use the limits written in this example. Passing a check does not establish that the model covers every load, material behavior, or operating condition in a real design.

Download this .napkin example ↓

Take it further with your agent

Napkin keeps the inputs, equations, checks and assumptions together in one study. Your agent sets it up; you change the numbers.

Try with Claude ↗

codex 'Use Napkin (https://napkin.engineering/mcp, or the local Napkin plugin) to build a study: Compressed-air receiver sizing. Inputs: demand excursion; pressure bounds; time; temperature assumption. Outputs: receiver volume; pressure decay. Model scope: Pressure, flow and actuator geometry with compressibility assumptions. Read napkin_capabilities and the current snapshot. Ask me for the values that matter, label assumptions with units, author .napkin source, validate it and apply it with napkin_source using the current revision, then open the study. Add checks for the limits I supply. Keep unsupported analyses explicit.'

Claude needs the Napkin connector; Codex needs the Napkin plugin. Set up your agent ↗

The broader study

The topic brief below describes the broader scope. The worked example above states the particular calculation it implements.

Inputs: demand excursion, pressure bounds, time, temperature assumption
Outputs: receiver volume, pressure decay
Modes: calculate, compare, sweep
Drawing: Actuator and circuit diagram

EXECUTABLE WORKED EXAMPLE · FIRST-ORDER MODEL · CHECK THE SCOPE & ASSUMPTIONS