Maintenance
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2019 – Valeport Ltd
5.3.
Impeller
The impeller should be free to rotate. Positioning the instrument vertically and spinning the impeller can test
this. Note that when the instrument is horizontal and not in water, the bearings are dry and the impeller is
not neutrally buoyant, so the impeller may not rotate freely.
To Remove the Impeller:
1.
Remove the impeller guard by unscrewing the guard away from the main body.
2.
Remove the impeller nose cap [yellow]
3.
Remove the two M3 nuts from the impeller shaft
4.
Slide the impeller off the shaft
5.3.1.
Cleaning:
Wash the inside of the impeller, and clean any residue from the impeller shaft.
5.3.2.
Impeller Shaft:
If it is required to reset the impeller shaft, it is necessary to set its position to ensure correct operation:
1.
Position the instrument with the shaft pointing upwards with the shaft in approximately the correct
position
2.
Without the guard fitted, replace the impeller on the shaft with the nose cone fitted
3.
Unscrew the nose cone to allow the impeller to rest against the instrument body hub face
4.
Lightly hold down the impeller down against the hub face, and slowly screw down the nose cone until it
tightens and thereby wants to lift the impeller away from the hub face
5.
Check the clearance between nose cone and impeller end face and adjust the shaft so that the clearance
is 0.5 to 0.75mm. Ensure the shaft and lock nut are tightened and recheck the gap.
6.
Refit the nose cone and impeller.
5.3.3.
Refitting the Impeller
This is a reversal of removal.
5.4.
General
The external parts of the meter are manufactured from titanium and polymers and are therefore corrosion
resistant. The titanium will become dull in appearance with use. The sensor end should be kept clean from
mud and debris to maintain accuracy of sensors. Washing off with clean water is therefore advised after use.
After use the impeller should be washed, and it is recommended that the impeller assembly is removed and
washed through to prevent the creation of salt deposits which will affect the subsequent performance of the
impeller.
Should problems be encountered with the instrument, then Valeport Limited should be contacted
immediately. Valeport will then be pleased to advise on the correct course of action.
Tel:
+44(0)1803 869292
E-Mail: