Pumps/pumping inlet piping configuration

Inlet Piping Configurations. An incorrect piping configuration can create undesirable flow distortions that, especiaUy for double-suction pumps, means turbulence. Air pockets trapped in the pipe can cause uneven flow, vibrations, and pump damage. 

Centrifugal pumps are highly susceptible to turbulent flow. The Hydraulic Institute provides guidelines for piping configurations that are specifically designed to ensure laminar flow of the liquid as it enters the pump. As a rule, the suction pipe should provide a straight, unrestricted run that is six times the inlet diameter of the pump. 

As far as maintenance is concerned, the pump motors must be lubricated periodically, and the pump must not be operated without liquid in it. The inlet piping must be designed to prevent cavitation. A metering pump should be calibrated not only before it is first used, but also periodically during its operation. The calibration should duplicate fluid properties, suction and discharge pressures, and inlet and outlet piping configuration. 

End-suction and multi-stage pumps with in-line impellers are prone to excessive axial thrusting. In the end-suction pump, the centerline axial inlet configuration is the primary source of thrust. Restrictions in the suction piping, or low suction pressures, create a strong imbalance that forces the rotating element toward the inlet. 

CONFIGURATION Inlet current from upstream sources (pumps), ducting, paper/ oil interface Pipes Upper plenum paper/oil inter face, charge precipitation from upstream injaction Paper/oil interface, paper bulk, oil bulk... 

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