The Importance of Internal Clearances

Dr. Barry EricksonJustin Bjork

Flowserve Pump Division

AgendaPurposeEnd Suction PumpsDouble Suction PumpsMulti-Stage PumpsWear Rings

Purpose

Suction vs. Discharge PressuresEfficiencyThrust Loads

Suction vs. Discharge Pressures

End Suction Pumps

Vanes to CasingVanes to CoverThermal Expansion

Double Suction Pumps

Offset Wear RingsShuttling Effect

Multi-Stage Pumps

Opposing ImpellersEqual Pressure Loss

A Gap B GapLoose A Gap Eddy Flows =Axial VibrationTight B Gap Vane Passing Cavitation

Opposing Impellers

A Gap B Gap

Vane Passing Cavitation

Wear Rings

Lomakin EffectAlternate Materials

Discussion