Capillary tubes are used instead of thermal expansion valves. The length and diameter of the capillary tube is chosen to match the flow capacity of the tube to the pumping capacity of the compressor.

Capillary tubes are generally used as the metering device on small, fractional-horsepower refrigeration systems. Charging these systems with refrigerant requires a different procedure than those ...

Complementarily, a 2025 investigation into ammonia flow through capillary tubes under conditions of sudden expansion and contraction has provided new models to predict local pressure losses ...