Operating Manual
When fitting a rotorcase correct shimming is
critical. Shims are fitted between the rotorcase
and gearcase and are used to control the back
clearances between the rotor and rotorcase.
Plastic colour coded shims are used on all series
D pumps. If the pump has previously been
shimmed, the old shims may be reused provided
they are replaced in their original positions. It is
essential that equal shimming is used both top
and bottom of the rotorcase to ensure that equal
clearances are maintained across the rotor
faces.
To reassemble the rotorcase the following step
by step procedure should be used :-
- Check the seals are correctly fitted.
- If the rotorcase has previously been
shimmed, replace the old shims in their
original positions.
- Alternatively, if new shims are to be fitted
the shimming process commences with
'too few' shims. Fit the rotorcase and
torque up the gearcase nuts, fit the rotors
and tighten to the recommended torque.
With 'too few' shims fitted measure the
back clearances (the clearance between
the back of the rotors and rotorcase), and
determine the additional shimming required
to bring the clearance within tolerance.
Note : For the correct clearance dimensions
please contact your supplier.
- Fit the additional shims, and recheck the
clearances. If necessary repeat the above
exercise until the clearances come within
tolerance.
Care should be taken when sliding the rotorcase
over the shafts so as not to damage the
mechanical seals if fitted. When fitting the shims
ensure that similar clearances are achieved both
top and bottom of the rotorcase.
9.5 Fitting and Shimming the Rotorcase
9.6 Front Cover Reversal
The front cover of all pumps in the series D range
is of a flat and symmetrical design thus making it
reversible. Therefore, when the inside face of
the front cover becomes worn it may be reversed.
In due course both sides will become worn and
the cover will have to be replaced.
Isolate the driver/pump from all power and control
supplies. If any noxious products have been
pumped, the system should be purged.
Ensure isolating valves to the pump are closed.
Loosen and remove the front cover retaining
screws and remove the front cover.
In the case of D5 and D6 pumps loosen and
remove the screws which hold the front cover to
the hinge. Be sure to retain the washers fitted
under the screw heads. Thoroughly clean the
front cover. Inspect 'O' ring and replace if
necessary.
Before replacing front cover simply reverse it
such that the unworn side faces the pump. In the
case of the D5 pumps ensure that the cover is
orientated such that the hinge fixing holes line up
with the hinge.
In the case of D5 and D6 pumps refit the hinge to
the cover by refitting the hinge retaining screws,
make sure that the washers are refitted under the
screw heads. Ensure that the ends of the hinge
retaining screws are flush with the inside of the
front cover when fully tightened.
Fit front cover and tighten retaining screws to the
recommended torque values.
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