Watson-Marlow 720DuN User Manual
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29.2 Removing and refitting
an extension pumphead
The procedure for removing and refitting an extension pumphead is the same for
720R and 720RE first pumpheads.
Removing the extension pumphead
From the extension pumphead remove: the track securing bolt and both tracks
the M8 x 307mm socket head cap screws from the bottom left and bottom right
of the extension pumphead; the M8 x 16mm socket head cap screw from the
top right corner of the extension pumphead’s back plate.
Pull the extension pumphead away from the first pumphead.
Refitting the extension pumphead
Regrease the drive shaft dog of the extension pumphead with the grease sup-
plied. Apply thread locking compound to the M8 x 16mm socket head cap
screw in the top corner of the backplate of the extension pumphead.
Align the drive shaft dog of the extension pumphead with the slot in the drive
shaft of the first pumphead. Fit the extension pumphead to the first pumphead.
Ensure the backplate of the extension pumphead is flat against the frontplate
of the first pumphead. Lightly tighten the socket head cap screw in the top cor-
ner of the extension pumphead backplate with the 6mm Allen key provided.
Apply thread-locking compound to the double-length (M8 x 307mm) socket
head cap screws supplied, position them in the bottom corners of the extension
pumphead frontplate, and tighten them in sequence with the M8 cap screw in
the top corner of the backplate.
Reposition the track on the first pumphead.
Reposition the extension pumphead track on the
extension pumphead. Position the track securing
bolt.
Note
: When a second pumphead is fitted the maxi-
mum pressure for each channel should not exceed 1
bar (14.5 psi).
