The reducer located on the suction side of a horizontally mounted centrifugal pump should be what?

The reducer located on the suction side of a horizontally mounted centrifugal pump should be eccentric. This configuration is important because it helps to prevent the accumulation of air within the pump casing, which can negatively impact the pump's performance. An eccentric reducer allows for a flat side at the top, reducing the likelihood of air pockets forming as the flow transitions into the pump.

In centrifugal pumps, maintaining a steady flow with minimal disruptions is crucial for optimal operation. An eccentric reducer facilitates a smoother flow path, allowing for better cavitation performance and reducing the risk of turbulence. This design contributes to more efficient priming and minimizes the chances of the pump losing prime due to entrained air.

The other reducer types, while they may have their uses in specific applications, do not offer the same level of effectiveness on the suction side of a centrifugal pump as an eccentric reducer does. A concentric reducer, for instance, can potentially trap air bubbles, leading to performance issues, while segmented and tapered options may not provide the necessary flow characteristics needed for optimal operation in this context.