Servicing
Diaphragm pump N680 EX
34
Translation of Original Operation and Installation Instruction, english, KNF 325438 02/22
10. For ST head only:
Fit the new diaphragm (
17
) together with the PTFE washer (
16
) on the
conrod plate (
14
).
When fitting the diaphragm, ensure that the blue PTFE coating on
the diaphragm is facing upwards.
11. Only .13:
Insert the new O-ring (
11
) in the housing.
12. Only .13:
Insert the new O-ring (
12
) in the conrod plate (
14
).
13. Apply the adhesive around the threaded end of the retainer plate (
15
)
and screw the retainer plate into the connection rod.
While screwing in, turn the retainer plate back one turn to allow the
adhesive to spread onto both thread flanks (retainer plate and con-
rod plate).
For ST head only:
Ensure that the PTFE washer and the diaphragm are fully embed-
ded in the ridge on the retainer plate. Also take care that the PTFE
washer and the diaphragm do not slip while they are being screwed
in and are lying flush one on top of the other.
Attention: Note the use-by-date for the adhesive.
The adhesive may lose its effectiveness after the use-by-date has
passed.
14. Then securely tighten the retainer plate (
15
) with the wrench for re-
tainer plate (tightening torque: 20 Nm).
Attention: Observe the hardening time for the adhesive before
recommissioning the pump.
The hardening time for the adhesive is approx. 24 hours.
15. For two-headed pumps:
Perform steps 1 to 12 for the second pump head.
Changing reed valves
1. Loosen the two hexagon socket head cap screws (
6
).
2. Remove the head plate (
3
) from the intermediate plate (
18
).
Carefully set down the head plate and intermediate plate so as not
to damage their sealing edges.
3. Remove the two O-rings (
10
) from the intermediate plate (
18
).
4. Use a felt-tip pen to mark the position of the valve stopper on the pres-
sure side (
4
) relative to the intermediate plate (
18
); Remove the valve
stopper (
4
) and the reed valve on the pressure side (
5
) after loosening
the screw (
2
).
5. On the pressure side, assemble with new reed valve together with the
valve stopper according to the marking (tightening torque for screw (
2
):
1.5 Nm).
6. After loosening the screw (
7
), remove valve stopper on the suction side
(
8
) and the reed valve on the suction side (
9
) from the intermediate
plate (
18
).
7. On the suction side, assemble the new reed valve together with the
valve stopper (tightening torque for screw (
7
): 1.5 Nm).
8. For two-headed pumps:
Perform steps 1 to 4 for the second pump head.
