🔍 Key Concepts

• Radial thrust in centrifugal pumps and how a double volute affects it compared to a single volute • What happens to hydraulic forces on the impeller when operating away from design capacity (best efficiency point) • Relationship between radial thrust, shaft deflection, and impeller deflection

💭 Think About

• How does a double volute casing change the balance of radial hydraulic forces on the impeller compared to a single volute? • When you operate a centrifugal pump above its design (best efficiency) capacity, do radial forces generally increase or decrease? • If radial thrust increases, which component physically bends: the shaft, the impeller, or both—and how is that usually described in pump design discussions?

✅ Before You Answer

• Identify which casing type (single vs double volute) is typically used to reduce unbalanced radial loads on the impeller • Decide whether operating greater than design capacity tends to increase or decrease radial thrust • Check which answer choice most accurately describes the main effect: is the concern radial thrust itself, or the susceptibility to deflection of the shaft/impeller?