Servicing of Cold Water Extraction Pump

Customer: Collinsville Power Station

Location: Mackay, QLD

Case Study ID: CS-91

Date: November 2012

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Collinsville Power Station engaged Dowdens Pumping and Water Treatment to service and examined all pumping and water treatment systems in their building.

The Problem

A cold water extraction pump from Collinsville Power Station required was stripped and assessed in the Dowdens Pumping, and Water Treatment workshop and the following issues were found and recorded:

  • The pump’s wear rings were worn unevenly, indicating shaft run out
  • Shaft centre supports and lower support bushes were worn beyond safe tolerance
  • Gasket material was missing between the 1st and 2nd stage, revealing the pump housing had spread slightly in the centre
  • After the casing and cover survey was completed it was confirmed there was up to 0.028″ hollow in the casing and 0.026″ hollow in the cover – with an average 0.010″
  • Impellers worn on ring landings and required machining to suit new wear rings
  • The pump shaft had run out on the lower journal
  • A foreign object was found in 1st stage impeller (plastic drink bottle)
  • The 2nd stage impeller hub was severely damaged.

Our Solution

In House Service Undertaken:

  • Impellers were machined, and new wear rings were made
  • Damage hub was machined and fitted to 2nd stage impeller
  • Pump casings were machined flat
  • Wear ring and bush landings were ‘horizontal bored’
  • The entire internals of the pump were painted with a ceramic coating
  • Impellers were balanced
  • All bearings and shaft bushes were replaced
  • The pump was pressure tested
  • The pump was painted and detailed