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).
Fig. 18
Insert the suction-outlet valve units, checking
that they are fully inserted in the seat of the
Head. Then apply the valve covers and calibrate
the respective M10x25 screws with a torque
wrench at the specified 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 M10x110 head fixing screws as indicated in
Fig. 20.
Fig. 19
B) Separate the head from the pump casing.
19
Fig. 19/a
Fig. 19/b
Fig. 20