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What does an air dryer do in a modern air brake system?
- A.It dries the brake linings after rain
- B.It adds moisture to keep valve seals soft
- C.It replaces the need for air tanks entirely
- D.It removes moisture (and helps remove oil) from the compressed air before the air reaches the tanks, and purges the collected material in a discharge cycle
Correct answer
D. It removes moisture (and helps remove oil) from the compressed air before the air reaches the tanks, and purges the collected material in a discharge cycle
Why
By drying the air upstream, the dryer greatly reduces the water available to condense in reservoirs and valves. Its purge sound during operation is the collected moisture and contaminants being expelled.
Manual topic: Air Brakes - Air Dryers · From the Air Brakes practice bank (AB-221).