KNF LAB LABOPORT N 820 Mode D'emploi page 97

Servicing
42
Chemically-resistant Laboratory pump N820.18
1. Use a felt-tipped marker to draw a continuous line on the
pressure plate (2), head plate (3), and intermediate plate
(5). This prevents the parts from being incorrectly
mounted later on.
2. Slacken the external screws ( Fig. 9/4) of the pump heads.
3. Carefully remove the pump heads.
Replacing the diaphragm
With the pump, the diaphragms (6) are changed succes-
sively to ensure that the shim rings (7) are used in the
same quantity as previously.
1. Press down one diaphragm (6) so that the other di-
aphragm is in the upper change point.
2. Carefully turn the upper diaphragm (6) counterclockwise
by hand and remove it.
Make sure that the shim rings located between the di-
aphragm and connecting rod do not fall into the pump
housing.
Remove any shim rings that may be adhering to the di-
aphragms and place on the corresponding connecting
rod thread.
Prerequisite for ensuring the pneumatic performance of
the pump is that the same number of shim rings be
mounted as before.
3. Screw in the new diaphragm (6) by hand and tighten it by
hand.
4. Perform steps 1 to 4 for the second pump head.
Translation of Original Operating Instruction, English, KNF
317428-317425 09/20
EX