The pin valves on CO2 bottles operate like schrader valves on a tire. Pushing down the pin opens the valve. The pin valve actuator works by pushing down on the pin when you screw the on-off knob clockwise. Since CO2 is a liquid in the bottle and the regulator can’t regulate liquid, you must mount the bottle so that only gas and no liquid can get into the regulator. We recommend having a small tank between the regulator and the air valve.