Suck back valve performs two simultaneous functions. Being a normally closed valve, it requires air to actuate. When switching from the open back to the closed position, its unique design creates a vacuum on the discharge port and immediately "sucks back″ a predetermined amount of liquid. The adjustment knob on top of the valve gives excellent repeatability on the suckback volume. The suckback valve is the perfect solution for dispensing equipment to prevent dripping of solution from dispense nozzles. Photoresist, adhesive, acids, solvents, syrup and many other medias may be processed through this valve.