Owner's manual
disposed of.
Use only original KNF replacement
parts.
Parts and tools required:
1 Service Set (see section 7)
Screwdriver blade width 2 mm
Phillips screwdriver No. 2
Felt-tip pen.
Change the diaphragms and valve pla-
tes/sealings in the following sequence:
a) Preparatory steps
b) Removing pump head
c) Changing diaphragm
d) Changing valve plates/ sealings
e) Refitting pump head
f) Final steps.
The position numbers in the
following text refer to fig. 2.
a.) Preparatory Steps
Shut down system (see section 4.2)
including disconnecting the pump
from the power source (pull out
plug of pump).
Remove tubing from the inlet and
outlet connectors of the pump.
On the pneumatic head connec-
tions, loosen one of the union nuts
by hand. Then slightly loosen the
angle-fitting in the pump head by
turning it anticlockwise
, so that the
connecting tube can be pulled out
Undo the screws that hold the
fan cover (see fig. 1) and remove
the fan cover from the motor.
b) Removing pump head
(for each head separately)
Mark the position of top plate ,
head plate , intermediate plate
, and housing relative to each
other with a felt-tip pen. This is to
ensure that the parts will be re-
assembled cor rectly at a later
stage.
Undo the eight screws and lift
the pump head off the housing .
The solenoid valve of the
drying system remains fitted
in this situation.
c) Changing diaphragm
Position the pump so that the dia-
phragm surface is upwards.
Turn the fan to bring the structured
diaphragm to top dead centre.
Using a small screwdriver, bet-
ween the housing and the outer
edge of the structured diaphragm,
carefully lift the edge of the dia-
phragm lightly upwards at one
point (making sure not to damage
the housing). Now grip the edge of
the diaphragm on opposite sides,
unscrew it by turning anti-clock-
wise.
Take the diaphragm spacer(s) off
the connecting rod and retain
them.
Check that all parts are free from
dirt and clean them if necessary.
Put the diaphragm spacer(s)
on the thread of the new dia-
phragm.
Fit the new structured diaphragm
: hold the connecting rod with
one finger, and gently screw in
(clockwise) the structured dia-
phragm with diaphragm spacers.
Turn the fan until the structured
diaphragm is at the top dead cent-
re. Using a small screwdriver, bet-
ween the housing and the outer
edge of the structured diaphragm,
carefully lift the edge of the dia-
phragm lightly upwards at one
point. Now grip the edge of the dia-
phragm on opposite sides (do not
overstretch the diaphragm!) and
tighten the structured diaphragm
clock-wise.
d) Changing valve plates/sealings
Undo the two screws .
Separate the head plate with
top plate from intermediate
plate .
Remove the valve plates/sealings
from the intermediate plate.
Check that the valve seats, the
head plate and intermediate plate
are clean. If scratches, distortion,
or corrosion are evident on these
parts they should be replaced.
Lay the new valve plates/sealings
in the recesses in the interme-
diate plate. The valve plates/sea-
lings for suction and pressure sides
are identical, as are upper and
lower sides of the plates/sealings.
e) Refitting pump head
Turn the fan to bring the structured
diaphragm to medium position.
Place the intermediate plate ,
with valve plates/sealings on
the housing, in the position indica-
ted by the felt-tip pen marking.
Place the head plate on the
intermediate plate in the posi-
tion indicated by the felt-tip pen
marking.
Place top plate in position
PM 16527-860.3-2.00 e 11/05
4
X
X
Fig. 2: Cross section of pump heads (symbolic)
Specification
Pos Description
Top plate
Head plate
Intermediate plate
Housing
Cross recessed raised counter-
sunk head screw
Structured diaphragm
Diaphragm spacers(s)
Connecting rod
Cross recessed raised cheese
head screw
Disk spring
Valve plate/Sealing