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How is a typical manual tank drain valve operated?
- A.By removing the valve completely from the tank
- B.By striking the tank until it vibrates
- C.By pulling a lanyard or cable, or turning the valve as designed, and holding it open until the discharge changes from liquid and debris to clean air
- D.By loosening a brake chamber fitting instead
Correct answer
C. By pulling a lanyard or cable, or turning the valve as designed, and holding it open until the discharge changes from liquid and debris to clean air
Why
The drain must stay open long enough for pressure to blow out the water and sludge that settle at the bottom of the tank. Closing it at the first hiss leaves most of the collected liquid behind.
Manual topic: Air Brakes - Air Tanks and Draining · From the Air Brakes practice bank (AB-224).