POCKET BOOK_Final_Turned - Pall Corporation

Flushing Procedures and FormulaThe aim of flushing is to remove contamination from the inside of pipes andcomponents which are introduced during system assembly or maintenance.This is accomplished by passing fluid through the system, usually at a velocityhigher than that during normal operation.Omission or curtailment of flushing will inevitably lead to rapid wearof components, malfunction and breakdown.Reynolds N o (Re): A non-dimensional number that provides a qualification of thedegree of turbulence within a pipe or hose.Laminar FlowTurbulent FlowLaminar Flow - Reynolds N o < 2,000Transitional Flow - Reynolds N o 2,000 - 4,000Turbulent Flow - Reynolds N o > 4,000The flow condition in a pipe or hose can be assessed using Reynolds N o as follows:Re = Ud x 1,000 or Re = 21,200 x Q / ( x d)Re = Reynolds N oU = Mean flow velocity (m/s)d = Pipe internal diameter (mm)= Kinematic viscosity of fluid in cSt (mm 2 /s)Q = Flow rate (L/min)32