🔍 Key Concepts

• Scavenging air system layout on a large low-speed diesel engine • Purpose and location of a non-return (check) valve in an air system • Relationship between the scavenge air receiver and the scavenge ports in the cylinder liner

💭 Think About

• Trace the path of air from the turbocharger/air receiver into the cylinder and note where backflow would be most dangerous. • Ask yourself: which labeled component is a valve placed to stop high-pressure combustion gases from flowing back into the scavenge manifold? • Compare which letters point to a space or chamber versus which point to a discrete valve body on a flanged connection.

✅ Before You Answer

• Identify which letter points to the scavenge air receiver itself (a large drum/space, not a valve). • Identify which letters clearly indicate moving valve components or valve housings on the air side, not exhaust or fuel valves. • Confirm that the component you choose lies between the scavenge receiver and the cylinder’s scavenge ports, where a non-return function would be needed.