sump pump quick disconnect

Tuesday Tip: How Proper Suction Piping Improves Pump Reliability and Performance

BEST PRACTICES FOR SUCTION PIPING

Use eccentric reducers with the flat side on top. This avoids trapping air at the reducer. Concentric reducers can hold air and lead to cavitation. Maintain straight, gradually sloped piping away from the pump. Suction lines should slope slightly downward to the pump. Horizontal pipe runs should be straight for at least four pipe diameters before entering the pump. Add flow straighteners for clear liquid applications. These devices help eliminate turbulence and uneven velocity distribution that can disrupt pump performance. Support the suction pipe independently. Do not hang the pump from the pipe. Unsupported pipe adds stress that leads to bearing misalignment, vibration, and early mechanical seal failure. Keep velocities between 3–8 ft/sec. This is general rule. This speed reduces friction losses and prevents vortexing at the inlet, but if you need to have a higher flow rate to reduce settling, you should use the increased flow –a plugged impeller is one of the worst suction side problems.

COMMON MISTAKES TO AVOID

Sloping piping toward the pump. This traps air, causing the pump to lose prime or cavitate. Using too many elbows, fittings, or 90° miters. Sharp bends and unnecessary fittings increase friction loss and create turbulent flow. Hanging the pump on unsupported suction piping. This leads to premature wear, leaks, and possible motor overload. Do not restrict flow with undersized piping. Sudden changes in pipe diameter increase entrance losses and reduce NPSHa (Net Positive Suction Head Available).

THE RESULTS OF GOOD PRACTICE

Good suction piping layout supports: Stable, efficient pump operation • Longer seal and bearing life • Better NPSH conditions • Fewer maintenance issues • Greater reliability in critical applications