Interpump Group Pratissoli WK12 Manual De Reparación página 21

2.2.2 Reassembling the head – valve units
Pay particular attention to the conditions of the
various components and replace if necessary,
and at the intervals indicated in the "PREVENTIVE
MAINTENANCE" table in chapter 11 of the Use and
maintenance manual.
At every valve inspection, replace all O-rings and all
anti-extrusion rings both in the valve units and on
the valve plugs.
Before repositioning the valve units, thoroughly
clean and dry the relative seats in the head as shown
in (Fig. 18).
To reassemble the various components, perform the
operations listed above in reverse order to par. 2.2.1. To
facilitate insertion of the valve guide in its housing, you can
use a bush resting on the horizontal guide planes and use a
hammer acting on the whole circumference (Fig. 19/a).
Do not invert the suction springs with the
previously disassembled outlet springs during
assembly of the suction and outlet valve units:
a) "White" suction springs.
b) "Black" outlet springs.
Fig. 18
Insert the suction and outlet valve units,
checking that they are fully inserted in the head
seat.
Then apply the valve covers and calibrate the
respective M12x35 screws torque wrench at the
required tightening torque.
2.2.3 Dismantling the head – seals
Replacement of the seals is necessary from the moment you
begin to detect water leaks from the drainage holes provided
on the back of the pump casing, and at the intervals indicated
in the "PREVENTIVE MAINTENANCE" table in chapter 11 of the
Use and maintenance manual.
A) Unscrew the M12x150 head fixing screws as indicated in
Fig. 20.
Fig. 19
B) Separate the head from the pump casing.
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Fig. 19/a
Fig. 19/b
Fig. 20