🔍 Key Concepts

• Two-stage air compressor operation – what happens between the first and second stage (inter‑stage pressure) • Function of a suction (inlet) valve on the second stage and how a leak affects air flow • Relationship between inter‑stage pressure and each stage’s discharge pressure and temperature

💭 Think About

• Picture the compression cycle: if the second stage suction valve leaks, in which direction can air flow during the second stage compression stroke? • How would that leakage change the pressure in the space between stages (the inter‑stage receiver/aftercooler)? • If inter‑stage pressure rises, which stage has to work against the higher pressure, and which measured quantity on that stage would show this problem?

✅ Before You Answer

• Identify which component is directly connected to the second stage suction valve (hint: the inter‑stage/first stage discharge side). • Decide whether a leak at the second stage suction valve would more likely raise pressure before the second stage, after the second stage, or in the cooling section only. • Remember that excessively high temperature is usually tied to more work of compression, while excessively high pressure at a stage is tied to what that stage is compressing into.