The safety relief valve is designed to open at approximately 150 psi to protect the air system from over-pressurization. If the governor fails to cut out the compressor, the safety valve prevents dangerous pressure buildup.
The CDL (Commercial Driver License) exam tests your knowledge of commercial driving rules, safety procedures, and vehicle operation. You must score 80% or higher to pass the written knowledge test. The exam covers general knowledge, air brakes, combination vehicles, and various endorsements.
This question is from the Class B CDL Knowledge Test #2 section. Practice with more questions from this category to build confidence before taking the official DMV test.
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