Home › CDL Practice Tests › Air Brakes Questions › Question 52
What is the job of the safety valve?
- A.To warn the driver at low pressure
- B.To drain water automatically every day
- C.To apply the spring brakes at 60 psi
- D.To protect the tanks and system from over-pressurization if the governor fails to cut out the compressor
Correct answer
D. To protect the tanks and system from over-pressurization if the governor fails to cut out the compressor
Why
The valve simply opens against a spring when pressure exceeds its setting and reseats when pressure falls. Its operation is a symptom of a control failure, never a normal way to regulate pressure.
Manual topic: Air Brakes - Safety Valve and Low Pressure Warning · From the Air Brakes practice bank (AB-052).