Why should suction piping be designed to minimize friction losses and avoid air pockets?

• A. To reduce noise in the system.
• B. To avoid cavitation and maintain prime, improving efficiency.
• C. To simplify installation.
• D. To require less maintenance.

Answer: (B)

The suction side must keep fluid pressure high enough to prevent cavitation and to keep the pump primed. Friction losses in the suction piping and any air pockets reduce the pressure at the pump inlet. If the inlet pressure drops toward the liquid’s vapor pressure, tiny vapor bubbles form and collapse, causing cavitation that damages the impeller, reduces flow, and lowers efficiency. Air pockets break the continuous column of liquid, causing loss of prime in pumps that rely on a full suction line. By designing suction piping to minimize friction and to avoid air pockets, you maintain a steadier, higher inlet pressure, keep the pump primed, and improve overall efficiency.

Other potential benefits like quieter operation, easier installation, or lower maintenance are not the primary reason for this design focus; they may occur, but the central purpose is preventing cavitation and preserving prime.