Abstract: A dispensing system includes a hollow tube having an outer wall with an air vent formed in the outer wall. A valve including a flexible flap is disposed inside the tube. The flexible flap, normally biased into a retracted position, is moveable between an extended position for sealing the air vent and the retracted position for unsealing the air vent. A syringe connector interconnects a syringe with the proximal end of the hollow tube and defines a fluid flow path. A flowable viscous fluid is disposed within the syringe. When a syringe plunger is depressed, the flowable viscous fluid is expelled from the syringe and forced through the fluid flow path and into the proximal end of the hollow tube. When the flowable viscous fluid engages the flexible flap, the flexible flap is forced to move into a position that seals the air vent.