What component is primarily responsible for storing compressed air in an air brake system?

In an air brake system, the component primarily responsible for storing compressed air is the reservoir. The reservoir, often referred to as an air tank, holds compressed air until it is needed in the braking system. This stored air is essential for the operation of the brakes, as it provides the necessary pressure to engage and release the brake chambers.

A well-functioning reservoir ensures that there is always a supply of compressed air available, which is crucial for safe and effective braking, especially in heavy vehicles or during frequent stops. The reservoir also serves as a buffer to handle fluctuations in air pressure, contributing to the overall reliability of the braking system.

Other components like the foot valve, brake chamber, and governor have their own important functions, but they do not primarily serve the purpose of storing compressed air. The foot valve regulates the flow of air in response to the driver's inputs, the brake chamber converts the air pressure into mechanical force to apply the brakes, and the governor controls the air pressure in the system to maintain proper operation. Each of these components plays a role in the system, but the reservoir is specifically designated for the storage of compressed air.