Refrigerant Capillary Tube Calculator

Your details

Tube Resizer finds the new tube length when you swap to a different bore diameter. Flow Analysis solves for mass flow rate and related parameters given pressures and geometry.
Internal diameter of the original capillary tube.
mm
Length of the original capillary tube.
m
Internal diameter of the replacement capillary tube.
mm
New tube length
3.406m

Equivalent capillary tube length for the new diameter

Length ratio (new / original)1.703

Replace 2.00 m of 1.63 mm tube with 3.406 m of 1.83 mm tube.

  • The new tube must be longer because a larger bore changes flow resistance by the 4.6-power law.
  • Length ratio is 1.703: the replacement tube is 70.3% longer than the original.
  • Small changes in diameter have a large effect: halving the diameter reduces flow by 2^4.6 = about 24-fold.
  • Always verify the replacement matches your system's design refrigerant mass flow rate using a flow analysis.

Next stepSwitch to Flow Analysis mode to confirm the resized tube delivers the correct mass flow for your operating pressures.

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