🔍 Key Concepts

• Centrifugal fire pump operating principles (flow vs. pressure) • Effect of throttling on suction vs. discharge side of a pump • Purpose and normal use of a relief valve on a fire main system

💭 Think About

• Think about what happens to a centrifugal pump if you restrict flow on the suction side—how does that affect pump performance and risk of damage? • Which action allows you to safely control flow and pressure leaving the pump without starving it of water? • What is the normal function of a relief valve in a fire main system—continuous adjustment for capacity, or over‑pressure protection?

✅ Before You Answer

• Verify which side of the pump is normally throttled in practice: suction or discharge • Consider which option could lead to cavitation or overheating of the pump • Identify which component is designed mainly for over‑pressure protection, not routine flow control