🔍 Key Concepts

• Starting air system flow path from manifold → distributor → cylinder inlet • Function of a check (non-return) valve in preventing reverse flow • Difference between a system control valve and individual cylinder valves in the illustration

💭 Think About

• Trace the arrows in the illustration and decide at which component compression pressure would first try to flow back toward the manifold • Ask yourself which component is designed as a one-way valve at each cylinder, and which components simply open/close to admit air • Consider whether high pressure alone can stop gas from flowing backward, or whether a specific mechanical feature is needed

✅ Before You Answer

• Identify on the sketch which part is installed directly at the cylinder head air entry • Decide which listed component has an internal non-return (spring‑loaded or mechanically seated) design • Confirm that the device you choose would still prevent backflow even if the rest of the starting system piping were open