Parenteral fluid administration set

A parenteral fluid administration set for administering a parenteral fluid intravenously at a controllable uniform flow-rate from comprising a source of said fluid, a flow regulator to which said fluid flows from said source by gravity, said flow regulator comprising an upright fluid-collecting container, an open-ended tube having substantially lesser axial length than the height of said fluid container affixed to and extending uprightly from and opening through the container bottom wall, the upper open end of the tube determining the maximum level of the fluid flowing to and collecting in said container, with any overflow passing downwardly through the tube and collecting in an elongated receiving reservoir affixed to and depending from the bottom-end wall of the aforesaid fluid container, a floating siphon disposed in said container including a float member riding on the surface of the body of fluid collecting in the container and a siphon affixed to said float so as to be movable vertically as one with said float, the shorter leg of the siphon extending downwardly through the float member with its end opening into the fluid on which the float member rides, the longer leg of the siphon extending downwardly through said upright open-ended tube to and with its end opening into a siphon priming bulb disposed in the upper end of the receiving reservoir, means for aseptically priming said siphon including said bulb and means depending therefrom for closing off the lower end of said bulb, the construction and arrangement being such that upon flow being established through the siphon, said floating siphon operates to maintain constant both the vertical distance between the siphon intake and the surface of the fluid in the fluid container and the vertical distance between said siphon intake and the siphon outlet, and tubing means connected to the lower end of the receiving reservoir and extending to an injection needle.