3/4" PVDF Venturi Injector When pressurized water enters the injector inlet, it is constricted toward the injection chamber and changes into a high-velocity jet stream. The increase in velocity through the injection chamber results in a decrease in absolute pressure, creating a vacuum, thereby enabling an additive material to be drawn through the suction port and entrained into the water stream. As the jet stream is diffused toward the injector outlet, its velocity is reduced and it is reconverted into lower pressure energy. Brand New In The Poly Bag 3/4 Inch Venturi For Spa and Hot Tub Ozone Generator For Swimming Pool Ozonator For Water Treatment, Pond or Lake Aeration