🔍 Key Concepts

• Reciprocating air compressor valve operation – difference between intake (suction) and discharge valves • Normal direction of air flow through the inlet filter and into the cylinder during the suction stroke • What happens if an intake or discharge valve is damaged or not sealing properly while the piston is moving

💭 Think About

• On which stroke should air be moving into the cylinder through the inlet filter, and on which stroke is the air being compressed? Think about the direction of air flow on each stroke. • If air is blowing backwards out of the inlet filter while running, which component would allow high‑pressure air from the cylinder to return toward the inlet? • Would a dirty filter or high compression alone reverse airflow, or would something need to let compressed air leak back toward the intake side?

✅ Before You Answer

• Identify which part (intake valve, discharge valve, or filter) controls flow from the inlet into the cylinder. • Consider which fault would allow compressed air to leak back past the valve toward the inlet during the compression stroke. • Eliminate any options that only increase resistance to flow (like restriction) but do not create a reverse flow path.