At what psi should the park control valve activate?

The park control valve is designed to engage at a psi range that ensures sufficient air pressure is available to properly apply the brakes and secure the vehicle when parking. Activating the park control valve within the range of 20-45 psi provides a safety mechanism that allows the brakes to hold the vehicle in place even under varying conditions, while still ensuring that the air brake system is operational if needed. This psi range acts as a threshold for optimal brake functionality, as pressures below this level may not engage the system reliably, implications involving safety and effective braking.

Understanding this range is crucial in air brake systems, as it balances between maintaining operational safety and establishing effective settings for parking. The pressure levels above and below this range could lead to improper engagement or disengagement of the brake system, potentially leading to unsafe conditions.