Fybroc Division series 1500 horizontal pumps - MHz Electronics, Inc

IMPELLER ADJUSTMENTThe horizontal 1500 series design permits adjustmentof the impeller clearance between the pumpcasing wall and the impeller face. The pumpimpeller is adjusted at the factory during assemblyand should not require further adjustment uponinstallation.Impeller adjustment will be required when a dropin head and/or capacity indicates a change inclearance, or when existing components of thepump are replaced. Refer to the following table forrecommended clearance when adjusting impelleron horizontal pumps.Impeller DiameterClearanceUp to 8" .015”8" to 10" .020”10" to 16" .025”A) Loosen set screws or other holding devices ifso provided on mechanical seals before adjustingimpeller to prevent seal face damage.B) Loosen the adjusting screws (Item 33A) evenly.C) Tighten up equally on the screws that threadinto the power-frame until you can feel theimpeller just starting to rub on the casing face.By rotating the shaft frequently by hand whiletaking up on the screws, you can determinewhen the impeller begins to bind.D) Back out the screws that thread into the powerframeuntil you can insert a feeler gauge undereach of the bolt heads to the recommendedclearance (See table above).E) Tighten the remaining adjusting jacking screwsuntil the gap left by the feeler gauge is gone.F) Check to be sure the shaft turns freely.G) Reset and tighten the mechanical seal per theseal manufacturers instructions.NOTE: Frequent impeller adjustments torestore hydraulic performance are an indicationof increased internal clearances. Excessiveclearance behind the impeller will result inexcessive thrust loads in high pressure pumpsleading to reduced outboard bearing life.Replace worn parts.16