Servicing
Diaphragm pump N87.9
24
Translation of Original Operating and Installation Instruction, english, KNF 121538-121541 11/22
4. Insert the new valve plates/seals (12) in the valve seats of the interme-
diate plates (6).
5. Place the head plate (5) on the intermediate plate according to the felt-
tip pen marking.
6. Check the centering of the head plate (5) by means of a slight lateral
movement.
7. Connect head plate (5) and intermediate plate (6). To do this, screw in
screws (3; Fig. 5: A + B) with disc spring (11) and shim rings (10) until
the screw head is seated flat, i.e., until the first resistance is encoun-
tered. Apply a small amount of thread locker (Loctite 222 or compara-
ble product) to the threads of the screws.
Fitting the pump head
Fig.5 Tightening cap head screws
1. Place the pump head on the housing according to the felt-tip pen mark-
ing.
2. Place the pressure plate (4) on the head plate according to the felt-tip
pen marking.
3. Screw in the screws (1) with disc spring (11) and slightly tighten them
crosswise in the order 1-2-3-4 (see Fig. 5) with 1 Nm.
4. Check for ease of movement of the pump by turning the counterweight.
5. Tighten the screws (1) with disc spring (11) crosswise in the order
1-2-3-4 (see Fig. 5). Tightening torque: 2.1 Nm.
6. Then tighten the screws (3; Fig. 5: A + B) another quarter turn (tight-
ening torque: 30 Ncm) and mount the screw covers (2).
Final steps
1. Mount the housing cover.
2. Check the pump head and pneumatic connections for leaks.
3. Properly dispose of the replaced structured diaphragm and valve
plates/seals.
To ensure the required gas tightness of the pump following servic-
ing, a leak test is to be performed.
WARNING
Risk of injury and poisoning from leaks
à
Before recommissioning the pump, check the
pump heads and pneumatic connections for
leaks. Leaks may lead to poisoning, chemical
burns or similar injuries.
8.4 Changing the structured diaphragm and valve plates/
seals (S_-/A_ design based on project)
Requirements
à
Disconnect the drive from power and ensure that it is voltage-free.
à
Clean the pump and free the pump of hazardous materials.
Spare parts
Spare part*
Item designation**
Number per pump
head
Structured diaphragm
(7) in Fig. 7
1
Valve plates/seals
(12) in Fig. 7
2
Tab.15 *According to spare parts list, Chapter 10.1 Spare parts