After reducing brake pipe pressure by 20 psi, how long must you wait before monitoring for leakage?

When brake pipe pressure is reduced by a specific amount, such as 20 psi, it's essential to allow sufficient time for any potential leaks to present themselves. In this case, waiting for 1 minute provides an adequate duration to monitor for leakage effectively.

During this waiting period, the brake system stabilizes, and any leaks that may exist will manifest through a decline in pressure or audible sounds, allowing for adequate detection and assessment of the system's integrity.

This time frame is standardized in many procedures to ensure that operators can accurately evaluate the condition of the brake system after pressure adjustments. A shorter time might not allow enough opportunity for leaks to become evident, leading to safety risks, while a longer time would be unnecessary for monitoring purposes. Thus, the 1-minute wait is both practical and aligned with standard safety protocols in rail operations.