KNF LABOPORT N820.18 Originalbetriebsanleitung Seite 113

Chemically-resistant Laboratory pump N820.18 / N840.18
Translation of Original Operating Instruction, KNF 317428-317425 02/23
3. Replace the two O-rings on the connection tube (10/Fig.
10).
4. Loosen the internal head screw (1) on both pump heads.
5. Remove the two pressure plates (2) together with the two
internal head screws (1).
6. Unscrew the gas ballast (9/Fig. 10) from the head plate
(3).
7. Replace the O-ring on the gas ballast (9/Fig. 10).
8. Screw the gas ballast (9/Fig. 10) into the corresponding
head plate (3) as far as it will go. Then turn it back again
until the surface is oriented upwards.
9. Unscrew the hose connections (11/Fig. 10) from the head
plate (3) using the tool supplied.
10. Replace the O-rings on the hose connections (11/Fig. 10).
11. Screw the hose connections (11/Fig. 10) into the head
plate (3) hand-tight using the tool supplied.
12. Dispose of the replaced O-rings properly.
Replacing valve plates/seals
With the pump, the valve plates/seals (4) are replaced
successively.
1. Remove the head plate (3) from the intermediate plate (6).
2. Remove the old valve plates/seals (4).
3. Carefully clean the intermediate plate (6) (if there are de-
posits on it).
4. Insert the new valve plates/seals (4) into the correspond-
ing seats on the intermediate plate (6).
The valves and O-rings for the pressure side and suction
side are identical; the same applies for the top and bot-
tom of the valves and O-rings.
5. Perform steps 1 – 4 for the second pump head.
6. Dispose of the old diaphragm (7) and valve plates/seals
(4) properly.
7. Insert the connection tube (10/Fig. 10) into the head plate
(3).
Servicing
DE
EN
FR
ES
IT
49