A contrast media delivery system having a flow regulator assembly that allows a practitioner to regulate the passage of contrast media into a burette while minimizing turbulence and the formation of microbubbles in the contrast media. The flow regulator assembly can be actuated by twisting a rotatable cap. When the rotatable cap is released, the flow of contrast media from the inlet to the burette is stopped. A diffuser having a contact surface is provided which disperses contrast media as it passes into the burette to ensure that the contrast media flows smoothly and uniformly down the wall of the burette and into the volume of contrast media. A float and seating assembly which provides optimal sealing of the outlet of the burette while also allowing separation of the float from the seat when the burette is being refilled with contrast media.
