Air leakage can also brake the car? Why use the four-circuit protection valve?

Air leakage can also brake the car? Why use the four-circuit protection valve?

The braking system of trucks is usually divided into oil brakes and air brakes. The response speed of the oil brake is a little slow, and the strength is low. Generally, the oil brake is mostly used in models such as micro-faces and micro-trucks. It is characterized by small size, light weight and simple structure. The air brake has a quick response and strong braking force. It is mostly used in medium and heavy trucks. There are large parts such as air storage tanks and brake cylinders. Now many light trucks have also changed from oil brakes to air brakes. The four-circuit protection valve exists in the air brake system and is used to divert and protect the air pressure pipeline of the vehicle.  
● Why do trucks use four-circuit protection valves?
Why do trucks need to be equipped with four-circuit protection valves? In fact, it is to ensure the reliability of the vehicle braking system. When a pipeline is damaged, the four-circuit protection valve will protect other gas circuits from being affected, and still maintain the function of the brake to avoid traffic accidents.