Which of the following components operates within a pressure range of 5 to 80 psi?

The foot valve is a critical component in air brake systems, specifically designed to operate within a pressure range of 5 to 80 psi. This valve is responsible for controlling the flow of compressed air in the braking system when the driver applies the brakes. When the brake pedal is pressed, the foot valve allows air to flow into the brake chambers, creating the necessary pressure to apply the brakes effectively.

Operating within this specific pressure range ensures that the foot valve can respond appropriately to the driver's inputs, providing reliable braking performance. If the pressure were to fall below or exceed this range, the foot valve may not function correctly, leading to compromised braking efficiency and safety.

Other components, like the relay valve and purge valve, have different operational pressure ranges or functions within the brake system that do not align with the specific 5 to 80 psi range characteristic of the foot valve. Understanding these parameters is essential for diagnosing issues and ensuring the proper maintenance of the braking system.