How does one conduct the Brake Pipe Leakage Method?

How does one conduct the Brake Pipe Leakage Method?

• A. Charge brake system to 75 psi, after signal received, reduce pressure by 20 psi, after brake pipe exhaust stops--wait one minute, cut-out the automatic brake valve, wait an additional minute for brake pressure to equalize, time the brake pipe leakage for one minute. If leakage does not exceed 5 psi then test CW. If it does, check for leaks and retest.
• B. Charge brake system to 30 psi, release all air.
• C. Charge to 75 psi, immediately cut out the automatic brake valve.
• D. Charge to 75 psi, measure leakage for 15 seconds.

Answer: (A)

The Brake Pipe Leakage Method checks how quickly air leaks from the brake pipe when it’s isolated at a standard pressure, ensuring the leakage is within allowable limits. You start by charging the brake system to a standard 75 psi. After the signal is given, you reduce the brake pipe pressure by 20 psi (down to 55 psi) and observe until the brake pipe exhaust stops, confirming there isn’t ongoing venting that would skew the reading. Then you cut out the automatic brake valve to isolate the brake pipe and allow the brake pressure to equalize over a further minute. Finally, you time the brake pipe leakage for one minute. If the loss is no more than 5 psi in that minute, the test passes. If the leakage exceeds 5 psi, you need to check for leaks and retest. The other options miss key parts: they don’t use the correct initial pressure, the required 20 psi drop, the wait for exhaust to stop, the valve cut-out and equalization step, or the one-minute leakage measurement, so they don’t provide an accurate assessment of the brake pipe leakage rate.

The Brake Pipe Leakage Method checks how quickly air leaks from the brake pipe when it’s isolated at a standard pressure, ensuring the leakage is within allowable limits.

You start by charging the brake system to a standard 75 psi. After the signal is given, you reduce the brake pipe pressure by 20 psi (down to 55 psi) and observe until the brake pipe exhaust stops, confirming there isn’t ongoing venting that would skew the reading. Then you cut out the automatic brake valve to isolate the brake pipe and allow the brake pressure to equalize over a further minute. Finally, you time the brake pipe leakage for one minute. If the loss is no more than 5 psi in that minute, the test passes. If the leakage exceeds 5 psi, you need to check for leaks and retest.

The other options miss key parts: they don’t use the correct initial pressure, the required 20 psi drop, the wait for exhaust to stop, the valve cut-out and equalization step, or the one-minute leakage measurement, so they don’t provide an accurate assessment of the brake pipe leakage rate.