At each car, which component senses the increase in pressure during the braking process?

At each car, which component senses the increase in pressure during the braking process?

• A. Brake cylinder
• B. Control valve
• C. Reservoir
• D. Main valve

Answer: (B)

The correct answer is the control valve. This component is crucial as it is responsible for managing the application and release of the brakes on each rail car. During the braking process, as the application occurs, the control valve senses the increase in air pressure that is transmitted from the locomotive through the air brake system. When the engineer applies the brakes, the control valve detects the change in pressure within the brake pipe. It responds by allowing air to flow from the reservoirs into the brake cylinders, which then applies the brakes on the car. This process helps ensure that the brakes are engaged effectively and can be released when necessary. The other components play different roles in the air brake system. The brake cylinder is where the pressure is converted into mechanical force to apply the brakes, while the reservoir stores compressed air for braking. The main valve regulates airflow but is not the primary sensing component during braking. Thus, the control valve is the key element that senses increased pressure and manages the braking process efficiently.

The correct answer is the control valve. This component is crucial as it is responsible for managing the application and release of the brakes on each rail car. During the braking process, as the application occurs, the control valve senses the increase in air pressure that is transmitted from the locomotive through the air brake system.

When the engineer applies the brakes, the control valve detects the change in pressure within the brake pipe. It responds by allowing air to flow from the reservoirs into the brake cylinders, which then applies the brakes on the car. This process helps ensure that the brakes are engaged effectively and can be released when necessary.

The other components play different roles in the air brake system. The brake cylinder is where the pressure is converted into mechanical force to apply the brakes, while the reservoir stores compressed air for braking. The main valve regulates airflow but is not the primary sensing component during braking. Thus, the control valve is the key element that senses increased pressure and manages the braking process efficiently.