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

Correct Answer: Option A — cylinder air starting check valves

Cylinder air starting check valves are spring-loaded mechanical or pneumatic non-return valves mounted on each cylinder head. They automatically open under control air pressure during the start cycle but seal tightly against extreme cylinder compression and combustion pressures.