Servicing
34
3. Screw the new diaphragm (8) onto the connecting rod (9)
(clockwise) and hand tighten the diaphragm (8).
When screwing in the diaphragm (8), ensure that it is not
overtightened.
If the diaphragm is overtightened, there is a risk that it
could be damaged.
d.) Change valve plates
1. Separate the head plate (5) from the intermediate plate
(7).
2. Remove the valve plates/seals (6) from the head plate (5).
3. Please check the valve seats, intermediate plate (7) and
head plate (5) for cleanliness; replace these parts in the
event of unevenness, scratches or corrosion (contact your
KNF Customer Service in this case).
Insert the new valve plates/seals (6) in the valve seats of
the intermediate plate (7); the valve plates/seals (6) for
the pressure and suction side are identical; the same ap-
plies for the top and bottom of the valve plates/seals (6).
4. By slightly moving the valve plates/seals (6) horizontally,
make certain that they are not under tension.
5. Make certain that the valve plates/seals (6) are centered
in the valve seats of the intermediate plate (7).
6. Properly dispose of the replaced diaphragm, valve plates/
seals.
e.) Mount pump head
1. Place the intermediate plate (7) with valve plates/seals (6)
on the housing.
2. Place head plate (5) on intermediate plate (7) according to
the centering.
Place pump head on the compressor housing according
to the alignment of the gas connections.
3. Tighten the screws (4) crosswise (tightening torque:
190-200 Ncm).
Translation of Original Operating Instruction, KNF 323241-323242 06/22
Laboratory pump Laboport® N96