A valve for dispensing fluidic substance including a valve housing (12) defining a general axial flow path through the housing, a diaphragm (22) disposed in the valve housing substantially transverse to the axial flow path and defining first and second compartments (38, 39) therein, the diaphragm having a surface facing away from the flow path which includes an annular rib (32) and further having at least one aperture (34) disposed through the diaphragm in a peripheral arrangement outside of the annular rib for allowing passage of fluidic substance from the first compartment to the second compartment, a tubular seal mounted to the valve housing and having an inner end (46) which opens to face the annular rib of the diaphragm, an outer end (50), an annular lip (60) defining the inner end of the seal, and being annularly pivotable relative to the pivoting break sealing engagement between the diaphragm and the tubular seal so that fluidic substance in the second compartment is permitted access to the bore (44) of the tube, the outer end of the tubular seal having at least one orifice (52) for dispensing fluidic substance therefrom.