🔍 Key Concepts

• Net Positive Suction Head (NPSH) and why suction line losses must be minimized • How pipe diameter affects flow velocity and friction losses on the suction side of a pump • The purpose (and limits) of sloping suction lines toward the pump

💭 Think About

• Think about what a rotary (positive displacement) pump is most sensitive to on the SUCTION side: high friction loss, air leaks, or slight dimensional changes? • If you keep the same flow rate but change suction pipe size, what happens to velocity and friction loss in each choice (same size, larger, smaller)? • Would simply sloping the pipe toward the pump by itself solve the key suction-side problem the question is aiming at, or is something more fundamental about pipe size being tested?

✅ Before You Answer

• Compare how each option affects friction loss and the pump’s ability to get enough liquid (NPSH available) • Ask whether making the pipe smaller than the pump connection could ever be good practice on the suction side • Consider whether slope alone addresses the main design concern for rotary pump suction piping in exam-style best practice questions