General Pump MW Repair Manual - Manual (Page 40)

GENERAL PUMP
A member of the Interpump Group
MW/S SERIES
Page 40
2.2.4 Assembling the MWS45A, MWS50A and MWS55A Head-Valve Units
Pay particular attention to the conditions of the various components and replace if
necessary. At every valve inspection, replace all O-rings both in the valve unit and in
the valve plugs.
Before repositioning the valve unit, thoroughly clean and dry the relative housings on
head indicated by the arrows (1, fig. 144).
Proceed with reassembly following the reverse order indicated in point 2.1.3.
Assemble the suction and outlet valve units (fig. 145 and fig. 146).
To facilitate insertion of the valve guide in its housing, you can use a pipe resting on the horizontal guide
planes (fig. 147) and use an extractor hammer acting on the whole circumference.
Proceed with insertion of the valve units (suction and outlet) in the head, taking care to
follow the correct insertion sequence of O-rings and anti-extrusion rings.
fig. 144
Ref 300791 Rev.C
11-12