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Tube sizing

Compressed Air Tube ID Calculator

Estimate the minimum internal diameter needed to keep compressed-air velocity near a selected target at a given flow and pressure.

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Tube sizing

Run the calculation

Estimate the minimum internal diameter needed to keep compressed-air velocity near a selected target at a given flow and pressure.

Engineering inputsTube ID Calculator

Enter the known application values. Outputs update instantly as units or assumptions change.

Flow unit
Pressure unit
Use these values for preliminary sizing before final datasheet review.

Engineering visual

Tube ID Calculator calculation map

Airflow moves through a pipe with defined inside diameter and length; fittings and wall friction consume pressure along the route.

Tube ID Calculator calculation mapAirflow moves through a pipe with defined inside diameter and length; fittings and wall friction consume pressure along the route.PIPE LENGTH L + FITTINGSID DFLOW QPRESSURE LOSS Δp
  1. 01Free-air flow
  2. 02Calculate and compare
  3. 03Minimum tube ID
Calculated minimum ID
Nearest common ID
Working-pressure flow
Velocity target

Calculation reference

What this tool checks.

Free-air flow is converted to approximate actual flow at line pressure before calculating internal diameter.

Inputs

  • Free-air flow
  • Flow unit
  • Working pressure
  • Target velocity

Outputs

  • Minimum tube ID
  • Nearest common ID
  • Actual working flow
  • Velocity target

Engineering guide

Use the result with the right context.

Calculate tube id calculator from application data and interpret the result for preliminary pneumatic engineering review.

Calculation workflow

  1. Enter the known application values, including Free-air flow, Flow unit, Working pressure.

  2. Run the calculation using one consistent set of units and reference conditions.

  3. Review Minimum tube ID, Nearest common ID, Actual working flow, then compare the result with the component datasheet and application margin.

Assumptions and limits

  • Treat catalog flow coefficients and conductance values as component-specific data measured under stated reference conditions.

  • Validate tubing, fittings, silencers, manifolds, temperature, and simultaneous demand as part of the complete flow path.

FAQ

Common review questions.

01Tool noteWhy size tubing by velocity?

High compressed-air velocity can increase pressure drop, noise, and unstable response. Velocity sizing gives a quick first pass before detailed pressure-drop review.

02Tool noteIs tube OD the same as tube ID?

No. Pneumatic catalogs often list outside diameter, but the flow area depends on inside diameter. Check wall thickness or manufacturer data.

03Tool noteWhat should I verify after using the Tube ID Calculator?

Check the entered units and reference conditions, then compare the calculated outputs with manufacturer ratings, application safety margins, transient loads, installation losses, and measured machine performance.