Pneumatic Tubing Calculator

Size pneumatic tubing by calculating velocity, pressure drop, burst pressure (Barlow's formula), and recommended OD for air systems.

Air flow (SCFM)

Line pressure (PSI)

Tube run length (ft)

Allowable pressure drop (PSI)

Tube OD (in)

Wall thickness (in)

Material (1=nylon, 2=PU, 3=copper, 4=steel)

Number of fittings

Tab to move between fields

Air velocity (ft/s)

31.3

Total pressure drop (PSI)329.82

Burst pressure (PSI)2,080

Max working pressure (PSI)520

Tube ID (in)0.37

Recommended tube OD (in)0.63

Actual CFM (compressed)1.4

Straight-run drop (PSI)249.87

Velocity OkNo

Drop OkNo

How to Use This Calculator

Enter Air flow (SCFM), Line pressure (PSI), and Tube run length (ft).
Set Allowable pressure drop (PSI), Tube OD (in), and Wall thickness (in).
Adjust Material (1=nylon, 2=PU, 3=copper, 4=steel), Number of fittings as needed.
Review the Air velocity (ft/s) result.
Use Total pressure drop (PSI) and Burst pressure (PSI) to inform your decision.

How the result changes with Tube OD (in)

Air flow (SCFM): Standard cubic feet per minute of air demand.
Line pressure (PSI): Working pressure in the pneumatic line.
Tube run length (ft): Total straight-line tube length in feet.
Allowable pressure drop (PSI): Maximum acceptable pressure loss in the run.
Tube OD (in): Outside diameter of the tubing.
Wall thickness (in): Tube wall thickness.
Material (1=nylon, 2=PU, 3=copper, 4=steel): Tube material affects burst pressure rating.
Number of fittings: Push-to-connect or compression fittings in the run.

Air velocity (ft/s): Compressed air velocity in the tube (keep <30 ft/s for mains, <60 for branches).
Total pressure drop (PSI): Combined pressure loss from tube length and fittings.
Burst pressure (PSI): Calculated burst pressure from Barlow's formula.
Max working pressure (PSI): Burst pressure divided by 4:1 safety factor.
Tube ID (in): Calculated inner diameter (OD minus 2× wall thickness).
Recommended tube OD (in): Next standard tube OD that keeps velocity under 25 ft/s.
Actual CFM (compressed): Actual volume flow at operating pressure.
Straight-run drop (PSI): Pressure drop from tubing length only (excluding fittings).

Identify Input Parameters
4 parameters
Air flow (SCFM) = 10, Line pressure (PSI) = 90, Tube run length (ft) = 25, Allowable pressure drop (PSI) = 3 = 8 input(s) provided
Calculate Air velocity
Air velocity = velocityFtMin / 60
31.3 = 31.3
Calculate Total pressure drop
Total pressure drop = straightDrop + fittingDrop
329.82 = 329.82
Calculate Burst pressure
Burst pressure = (2 * tensileStrength * wallThickness) / tubeOd
2080 = 2080