Home › CDL Practice Tests › Air Brakes Questions › Question 51
At about what pressure does the safety valve on an air tank normally open to vent excess pressure?
- A.About 60 psi
- B.About 150 psi
- C.About 100 psi
- D.About 85 psi
Correct answer
B. About 150 psi
Why
The safety valve is set near 150 psi, above the governor cut-out range, as a last line of defense. If it is venting, the governor system has failed to stop the compressor and the truck needs repair.
Manual topic: Air Brakes - Safety Valve and Low Pressure Warning · From the Air Brakes practice bank (AB-051).