Servicing
Diaphragm pump N820.18 CN / N840.18 CN
34
Translation of Original Operating Instruction, KNF 317428-338560 06/22
4. Loosen the external cap screws (
4
/Fig. 7).
The two internal cap screws (
1
/Fig. 8) remain tightened
for the time being.
Removing pump head
1
Screw
2
Pressure
plate
3
Head cover
4
Valve plates/
seals
5
Locating pin
6
Intermediate
plate
7
Diaphragm
8
Shim rings
1
5
4
3
2
6
7
8
Fig.8: Pump head (pump N820 shown)
The following item numbers refer to Fig. 8 unless speci-
fied otherwise.
1. Mark the pressure plate (
2
), head cover (
3
) and intermedi-
ate plate (
6
) with a continuous pencil stroke. This prevents
the parts from being incorrectly mounted later on.
2. Loosen the external screws (
4
/Fig. 7) of the pump heads.
3. Carefully remove the pump heads.
