Valve assembly with chamber vent and fluid deflector

1. A media delivery system, comprising:

a burette comprising:

a chamber having an interior wall and inlet and outlet connections in fluid communication with the chamber;

a vent assembly configured for fluid communication with the chamber;

a float and seat assembly, comprising:

a buoyant float positioned in the chamber of the burette, the float being arranged for movement within the chamber; and

a seat assembly positioned in the chamber and configured to cooperate with the float to manage a flow of media through the outlet connection of the chamber; and

a diffusion plate configured to implement a substantially laminar flow in at least a portion of media entering the chamber through the inlet connection, the diffusion plate located in proximity to the inlet connection, the diffusion plate comprising:

a main body to provide an impact surface for droplets of media passing from the inlet connection into the chamber;

a shroud disposed around and attached to the main body, the shroud extending at least partially above the main body and sloping toward the interior wall, the shroud configured to receive at least a portion of media that splashes as a result of an impact of a droplet of media on the main body and to direct media disposed on the shroud toward the interior wall.

2. The media delivery system as recited in claim 1 , wherein the buoyant float is substantially symmetric about a predetermined axis.

3. The media delivery system as recited in claim 1 , wherein the buoyant float substantially comprises a single piece of material.

4. The media delivery system as recited in claim 1 , wherein the buoyant float defines an interior chamber.

5. The media delivery system as recited in claim 1 , wherein the seat assembly is in fluid communication with the fluid outlet of the chamber.

6. The media delivery system as recited in claim 1 , wherein:

the float is positioned on the seat when a first predetermined volume of media is present in the chamber; and

the float is off the seat when a second predetermined volume of media is present in the chamber.

7. The media delivery system as recited in claim 1 , wherein the float and seat facilitate implementation of a vacuum in the chamber when a predetermined amount of media is present in the chamber.

8. The media delivery system as recited in claim 1 , wherein the seat is configured to enable contact between media in the chamber and at least a portion of a bottom surface of the float when the float is positioned on the seat.

9. The media delivery system as recited in claim 1 , wherein at least a portion of the float is deformable.

10. A media delivery system, comprising:

a burette defining a chamber for containing a volume of media and having inlet and outlet connections in fluid communication with the chamber, and the burette further including a vent assembly configured for fluid communication with the chamber; and

a float and seat assembly, comprising:

a buoyant float positioned in the chamber of the burette, the float being arranged for movement within the chamber, the buoyant float comprising:

a first convex surface;

a second convex surface to provide an impact surface for droplets of media passing from the inlet connection into the drip chamber and conducting the media along the first surface of the buoyant float and into the volume of media in the chamber; and

a circumferential rim positioned between the second convex surface and the first convex surface, the circumferential rim having a diameter that is greater than a maximum distance between the first convex surface and the second convex surface, such that the buoyant float has a generally disk-like configuration; and

a seat assembly positioned in the chamber of the burette and configured to cooperate with the float to manage a flow of media through the outlet connection of the chamber.

11. The media delivery system as recited in claim 10 , wherein the seat comprises a plurality of projections between which respective media passageways are located.

12. The media delivery system as recited in claim 11 , wherein the media passageways of the seat enable contact between media in the chamber and at least a portion of a bottom surface of the float when the float is positioned on the seat.

13. The media delivery system as recited in claim 10 , wherein the buoyant float is substantially symmetric about a predetermined axis.

14. The media delivery system as recited in claim 10 , further comprising a diffusion plate positioned proximate the inlet to the chamber.

15. The media delivery system as recited in claim 14 , wherein the diffusion plate includes a shroud that is located proximate the inlet connection to the chamber.

16. The media delivery system as recited in claim 14 , wherein the diffusion plate defines a central portion about which a wall is disposed, the wall being punctuated by at least one media outlet, and the at least one media outlet being located proximate an interior wall of the burette chamber.

17. The media delivery system as recited in claim 10 , wherein the seat comprises a plurality of projections, each of which has a corresponding contact surface arranged to interface with a lower surface of the float.

18. A burette, comprising:

an inlet for providing inflow of media to the burette;

a drip chamber for containing a volume of media and a volume of air for permitting dissipation of air bubbles in the media;

an outlet for allowing passage of media from the drip chamber;

a buoyant float positioned in the drip chamber, the float comprising:

a first convex surface;

a second convex surface to provide an impact surface for droplets of media passing from the inlet into the drip chamber; and

a circumferential rim positioned between the second convex surface and the first convex surface, the circumferential rim having a diameter that is greater than a maximum distance between the first convex surface and the second convex surface, such that the buoyant float has a generally disk-like configuration; and

a seat configured to receive the float and create an airtight seal between the drip chamber and the outlet to prevent the passage of air into the outlet of the burette when there is insufficient media in the drip chamber to cause floatation of the buoyant float.