An intravenous delivery system comprising: a liquid source containing a liquid; tubing comprising: a first end connectable to the liquid source to receive the liquid from the liquid source; and a second end; a drip unit comprising a drip chamber, wherein the drip unit is connected to the liquid source to receive drops of the liquid from the liquid source within the drip chamber, wherein the drip unit is connected to the first end of the tubing to supply the liquid to the tubing via gravity feed and a vent cap comprising: a proximal end connectable to the second end of the tubing to receive the liquid from the tubing; a distal end comprising a hydrophobic membrane that is substantially impermeable to the liquid and substantially permeable to air; a chamber, defined by a chamber wall wherein the chamber is in communication with the hydrophobic membrane to facilitate passage of air from the liquid out of the vent cap through the hydrophobic membrane, wherein the hydrophobic membrane is positioned adjacent to the chamber, a vent cap luer lock extending from the proximal flare and having a threaded interface, wherein the luer lock comprises a female tapered fitting, wherein the chamber wall is shaped to have a proximal flare that provides the chamber wall with an interior diameter greater than the largest interior diameter of the vent cap luer lock, and an orifice formed in the chamber wall between the chamber and the vent cap luer lock, CHARACTERIZED IN THAT the chamber comprises a hydrophilic membrane that covers the orifice and defines a boundary between the chamber and the vent cap luer lock to retain the liquid within the chamber. a liquid source containing a liquid; tubing comprising: a first end connectable to the liquid source to receive the liquid from the liquid source; and a second end; a first end connectable to the liquid source to receive the liquid from the liquid source; and a second end; a drip unit comprising a drip chamber, wherein the drip unit is connected to the liquid source to receive drops of the liquid from the liquid source within the drip chamber, wherein the drip unit is connected to the first end of the tubing to supply the liquid to the tubing via gravity feed and a vent cap comprising: a proximal end connectable to the second end of the tubing to receive the liquid from the tubing; a distal end comprising a hydrophobic membrane that is substantially impermeable to the liquid and substantially permeable to air; a chamber, defined by a chamber wall wherein the chamber is in communication with the hydrophobic membrane to facilitate passage of air from the liquid out of the vent cap through the hydrophobic membrane, wherein the hydrophobic membrane is positioned adjacent to the chamber, a vent cap luer lock extending from the proximal flare and having a threaded interface, wherein the luer lock comprises a female tapered fitting, wherein the chamber wall is shaped to have a proximal flare that provides the chamber wall with an interior diameter greater than the largest interior diameter of the vent cap luer lock, and an orifice formed in the chamber wall between the chamber and the vent cap luer lock, CHARACTERIZED IN THAT the chamber comprises a hydrophilic membrane that covers the orifice and defines a boundary between the chamber and the vent cap luer lock to retain the liquid within the chamber. a proximal end connectable to the second end of the tubing to receive the liquid from the tubing; a distal end comprising a hydrophobic membrane that is substantially impermeable to the liquid and substantially permeable to air; a chamber, defined by a chamber wall wherein the chamber is in communication with the hydrophobic membrane to facilitate passage of air from the liquid out of the vent cap through the hydrophobic membrane, wherein the hydrophobic membrane is positioned adjacent to the chamber, a vent cap luer lock extending from the proximal flare and having a threaded interface, wherein the luer lock comprises a female tapered fitting, wherein the chamber wall is shaped to have a proximal flare that provides the chamber wall with an interior diameter greater than the largest interior diameter of the vent cap luer lock, and an orifice formed in the chamber wall between the chamber and the vent cap luer lock, CHARACTERIZED IN THAT the chamber comprises a hydrophilic membrane that covers the orifice and defines a boundary between the chamber and the vent cap luer lock to retain the liquid within the chamber.