A substrate processing system includes a processing chamber that includes a substrate support positioned therein. The substrate processing system includes a valve system fluidly coupled to the processing chamber and configured to control flow of gas into the processing chamber. The valve system includes a primary flow line and a first gas source flow line fluidly coupled to the primary flow line through a first gas source valve. The valve system includes a second gas source flow line fluidly coupled to the primary flow line through a second gas source valve. The first gas source valve and the second gas source valve are positioned in series within the primary flow line.