Convert capillary tube dimensions when changing tube diameter.
Tube Parameters
New Length
Enter dimensions to calculate
Quick Reference
L1Original Length
D1Original ID
D2New ID
Exponent4.6 (typical key)
Overview
This calculator helps HVAC technicians find the correct length for a replacement capillary tube when the original diameter tube is not available. It uses a conversion factor based on the flow characteristics.
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Pro Tips
Ensure you are using the INNER diameter (ID), not the outer diameter.
The formula used is L2 = L1 * (D2 / D1)^4.6
Always cut capillary tubes cleanly to avoid restricting flow.
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Fun Facts
"The capillary tube is the simplest type of expansion device."
"It has no moving parts and relies on friction and acceleration to drop pressure."
"The small diameter causes a high pressure drop as the refrigerant accelerates."
