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Oil Flush for Lube Oil System

Oil Flush for Lube Oil System

Oil Flush for Lube Oil System

Is there a rule of thumb to calculate flow requirements (i.e. velocity or flow rate) for initial flushing of lube oil piping for large rotating equipment (ID Fans for a large boiler)?  The installation will consist of 2" and 3 " field welded stainless piping. The need is to provide sufficent velocity to remove any "heavy" particulate from the piping.

RE: Oil Flush for Lube Oil System


Will you be using the circulation pumps from the new system or temporary pumps just for flushing ?

Based on the rule of thumb for boiler circulation and initial flush, if you can circulate at the design flow rate or better, you have it made.

Will you be using a "flushing liquid" that has a significantly different specific gravity than the operating liquid ? If so you may have to flush at a higher rate to ensure cleanliness.

You will, of course, be using temporary strainers/screens to catch particulate ?


RE: Oil Flush for Lube Oil System

You should try to keep the Reynolds number above 4000 during your flushing operation. You can calculate this as follows:

Nr = 3160 * GPM / (ViscosityCst * IDinches) or

Since the viscosity of oils changes so markedly with temperature it is difficult to give a simple, general "Rule of Thumb".


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