During the starting of a diesel engine, compression gases are prevented from backing into the air starting system, shown in the illustration, by the __________. MO-0046

Correct Answer: Option A — cylinder air starting check valves

Cylinder air starting check valves act as automatic non-return check valves. When starting air pressure is removed, high-pressure combustion gases attempt to enter the air manifold, but this pressure forces the check valve tightly onto its seat to protect the system.