An intravenous delivery system may have a liquid source containing a liquid, tubing, and a vent cap. The tubing may be connected to the liquid source and the vent cap to convey liquid from the liquid source to the vent cap. The vent cap may have a vent that is substantially impermeable to the liquid and permeable to air, and therefore releases air from the liquid from the vent cap. The vent cap may also have a chamber in communication with the vent. The chamber may have a volume selected to enable the chamber to receive a quantity of liquid from the tubing in which the air, if entrained in the liquid, is likely to reside after the tubing has been primed with the liquid.