a dispenser using a stopcock valve has a first and second chamber . the first chamber has a flow material and is pressurized with air . the first chamber is connected to a stopcock valve that holds a second chamber which has a pressure sensor when the stopcock valve is rotated to the proper orientation . the stopcock valve is then rotated to a dispensing position where the flow material is dispensed under pressure to an outlet . by using the air pressure sensor and by taking into consideration the volume of the second chamber , the amount of flow of material can be dosed out consistently .