- Small bore tube used for metering by controlling length and bore size. In refrigeration, a tube of small internal diameter used as a refrigerant pressure and flow control between high and low sides.
- Tube used to transmit pressure from the sensitive bulb of some temperature controls to the operating element.
- Refrigerating capillary tube is a tube of small bore [down to 0.020 in. i.d. (0.50 mm)] used for the simultaneous purposes of metering the refrigerant and of accomplishing the expansion process between condenser and evaporator in refrigerating systems.