En
gl
is
h (
G
B)
68
•
Spring-loaded DN 4/DN 8 valve:
– Unscrew the valve cover.
– Dismantle the inner parts (as shown in fig. 70).
Fig. 70
Spring-loaded DN 4 valve /
spring-loaded DN 8 valve
3. Clean all parts.
If faulty parts are detected, proceed as follows:
– Replace the valve (for stainless-steel valves:
inner valve parts).
For contents and product numbers of the
spare parts kits, contact Grundfos.
4. Re-assemble and refit the valve.
5. Remove the deaeration cartridge (1p, 2p, 3p)
under the discharge valve from the dosing head
using a pair of tweezers.
– Dismantle the cartridge.
– Clean the cartridge.
If faulty parts are detected, proceed as follows:
– Replace the deaeration cartridge.
For contents and product numbers of the
spare parts kits, contact Grundfos.
– Re-assemble the cartridge.
6. Refit all parts.
Fig. 71
Standard DN 4/DN 8 valve
10.4 Replacing the diaphragm
10.4.1 Resetting the diaphragm
When replacing the diaphragm, it must be at the
back dead point (end of suction stroke). As the
stroke usually ends at the front dead point, reset the
diaphragm as follows:
•
With the pump stopped (LED lights up red), press
the "Up" and "Down" buttons simultaneously.
– The diaphragm is reset.
10.4.2 Switching off the pump
1. Switch off the pump and disconnect it from the
power supply.
2. Depressurise the system.
3. Take suitable steps to ensure that the returning
dosing medium is safely collected.
10.4.3 Replacing the diaphragm
See fig. 72 or 73.
1. Loosen the four screws (1q + 2q) on the dosing
head (2).
2. Remove the dosing head (2).
3. Unscrew the diaphragm (Q) counter-clockwise.
– For pumps without Plus
3
system:
Replace the sealing diaphragm (3q),
intermediate ring (4q) and support disk (5q).
4. Screw in the new diaphragm (Q).
5. Replace the dosing head (2) and cross-tighten
the screws (1q + 2q).
Maximum torque:
DDI 0.4 - DDI 5.5: 2.1 Nm.
DDI 13.8 - DDI 20: 2.5 Nm.
6. Vent and start up the dosing pump.
TM
03
6
266
45
06
TM
03
6
267
45
06
T
M
03
62
68
45
0
6
DN 4
DN 8
3b
1p
2p
3p
Caution
The O-rings must be correctly placed in
the specified groove.
Observe the flow direction (indicated
by an arrow)!
Only tighten the valve by hand.
Warning
Risk of chemical burns!
Wear protective clothing (gloves and
goggles) when working on the dosing
head, connections or lines!
Do not allow any chemicals to leak
from the pump. Collect and dispose of
all chemicals correctly!
Note
If possible, rinse the dosing head,
e.g. by supplying it with water.
