What is the purpose of the device shown in...

🔍 Key Concepts

• Relationship between spring-loaded relief valves and internal engine spaces like crankcases • How a crankcase explosion relief valve is designed to operate (disc, spring, deflector/flame trap) • Differences between devices that control pressure versus those that control speed or boost intake air

💭 Think About

• Look at the large spring, hinged plate, and cover in the illustration: what would these parts do if pressure suddenly increased on one side? • Which of the answer choices involves briefly opening to vent gas, then reseating, rather than running continuously during normal operation? • Which systems in a diesel engine are at risk of dangerous internal explosions and need a one‑way vent with a flame‑arresting cover like the one drawn?

✅ Before You Answer

• Identify which side of the device is likely inside the engine crankcase and which side opens to the engine room/atmosphere. • Decide whether the device’s action would be continuous regulation (like a governor or lube oil regulator) or emergency safety relief. • Match the visible parts (spring, valve plate, deflector or flame trap) to the option that describes protecting a compartment from overpressure rather than controlling speed or boosting power.

What is the purpose of the device shown in the illustration? See illustration MO-0105.

Regulate lube oil pressure in a diesel engine.

Protect the crankcase from overpressure in the event of explosion.

Utilize exhaust gas pressure to supercharge a diesel engine.

Secure the engine in the event of dangerous over speed.

🔍 Key Concepts

💭 Think About

✅ Before You Answer