MAINTENANCE MANUAL
GP/146/99. Issue 9. October 2005
Section 4
HIGH-PRESSURE IMPELLER
To Remove
With the volute cover plate and the low pressure impeller removed (Section 3)
unscrew the twelve M10 socket head cap screws securing the high pressure impeller
cover plate. Insert 2 M8 socket screws into the extractor holes in the cover plate and
screw them in evenly until the cover plate moves forward. The cover plate can now
be lifted off. Remove the cover plate and high pressure impeller, using tool number
60275/05 where necessary. Clean the cover plate and pump body jointing faces.
Maintenance
The high pressure impeller requires precise setting to achieve its rated output and to
avoid possible trouble in service. If no new parts have been fitted, ie pump body,
mechanical seal assembly, cover plate or high pressure impeller, the original shims
as fitted to the pump shaft may be inserted and a check on clearances carried out as
detailed in (b) and (c) below. If any of the above components have been changed,
carry out the entire sequence as follows:
(a)
With the pump body assembled to the bearing housing, place the original
shims, or a selection of shims from the four available thicknesses (0.051mm,
0.127mm, 0.26mm and 0.381mm) (0.002in, 0.005in, 0.010in and 0.015in) on
to the drive shaft. The accumulative thickness of shims must total at least 1.0
mm before the impeller nut is tightened to ensure that the high pressure
impeller is not damaged.
(b)
On no account should the mechanical seal seating ring (mounted within the
rear face of the HP impeller) be disturbed unless replacement of mechanical
seal components is contemplated. The mating faces of the mechanical seal
components may be cleaned with a non-abrasive, non-oily cleaner and wiped
dry with a lint-free cloth. Before assembly, moisten the face of the carbon
seal with clean water. Slide the impeller on to the drive shaft, followed by
spacer Tool No 60275/03 onto the shaft, followed by the large shaft nut.
Tighten the nut.
©Hale Products Europe LTD, Warwick
GP/146/99
WTmaint - Issue9. 10-2005October 2005
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