The working principle of the distribution valve: the distribution valve controls the inflation and exhaust of the air cylinder according to the pressure change in the train tube, and realizes the braking, pressure maintenance or relief of the locomotive through the role of the directional valve and the action valve. The importance of the distribution valve in the air brake is just like the human heart. If a failure occurs, the function of the air brake of the entire vehicle will be completely invalid, and there is no guarantee of driving safety.

The role of the distribution valve: to play the role of connection and distribution. Each branch pipe is connected to the main pipe through a distribution valve, which is the connection function; and the source of the main pipe is distributed to each outgoing pipe through the distribution valve.