English (GB)
43
8.4.2 Dismantling the dosing head, diaphragm
and valves
This section refers to fig. 44-45.
1. Put on the stipulated personal protective
equipment.
2. Set pump to "Stop" operating state using the
[Start/stop] key.
3. Make system pressureless.
4. Take suitable steps to ensure that the returning
liquid is safely collected.
5. Empty dosing head and flush it if necessary.
6. Press the [Start/stop] and [100%] keys at the
same time to put the diaphragm into "out"
position.
– Symbol must be displayed (see fig. 17).
– If the "Stop after power failure" alarm is active,
acknowledge the alarm by opening the "Alarm"
main menu. Otherwise the diaphragm cannot
be moved.
7. Dismantle inlet, outlet and deaeration lines.
8. Unscrew valves on inlet and outlet side (4, 7).
9. Disconnect FlowControl or DLD signal
connection, if present. See fig. 13-14.
10. For plastic dosing head:
– Remove screws (6).
– Remove dosing head (5) together with cover
plate (6a).
11. For stainless steel dosing head:
– Remove screws (6) together with washers (6b).
– Remove dosing head (5).
12. Unscrew diaphragm (3) counter-clockwise and
remove it.
13. DDA 60-10:
– Remove flange (2) together with O-rings (2a,
2d).
14. DDA 120-7 / DDA 200-4:
– Remove intermediate ring (2c).
– Remove screws (2b) together with flange (2)
and O-ring (2a).
15. Make sure the drain opening (8) is not blocked or
soiled. Clean if necessary.
16. Check the safety diaphragm (10) for wear and
damage. If the safety diaphragm is damaged,
send the pump to Grundfos for repair. See
section 8.7 Repairs.
If nothing indicates that dosing liquid has entered the
pump housing, go on as described in section
8.4.3 Reassembling the dosing head, diaphragm and
valves. Otherwise proceed as described in section
8.6.2 Dosing liquid in the pump housing.
8.4.3 Reassembling the dosing head, diaphragm
and valves
The pump must only be reassembled, if nothing
indicates that dosing liquid has entered the pump
housing. Otherwise proceed as described in section
8.6.2 Dosing liquid in the pump housing.
This section refers to fig. 44-45.
1. DDA 60-10:
– Place new O-rings (2a, 2d) in the grooves at
flange (2) and make sure they are seated
correctly.
– Attach flange (2) observing alignment pin (12).
2. DDA 120-7 / DDA 200-4:
– Install flange (2) and new O-ring (2a) with
screws (2b) observing alignment pin (12).
Make sure the O-ring is seated correctly.
– Cross-tighten screws (2b) with a torque
wrench. Torque [Nm]: 6 (+ 1).
– Attach intermediate ring (2c) to flange (2)
observing alignment pin (12).
3. Screw on the new diaphragm (3) clockwise.
– Make sure the diaphragm is screwed on
completely and fully resting on extension piece
(11).
4. Press the [Start/stop] and [100%] keys at the
same time to put the diaphragm into "in" position.
– Symbol must be displayed (see fig. 17).
5. Attach dosing head (5).
– DDA 60-10: Observe alignment pin (12).
6. For plastic dosing head:
– Install screws (6) through cover plate (6a).
7. For stainless steel dosing head:
– Install screws (6) with washers (6b).
8. Cross-tighten screws (6) with a torque wrench.
– Torque [Nm]: 6 (+ 1).
9. Connect FlowControl or DLD signal connection, if
present. See fig. 13-14.
10. Install new valves (4, 7).
– Pay attention to the flow direction arrow.
– Make sure the O-rings are seated correctly.
11. Perform hydraulic connection. See section
5.2 Hydraulic connection.
12. Press the [Start/stop] key to leave the service
mode.
13. Deaerate the dosing pump. See section
6.4 Deaerating the pump.
14. Observe the notes on commissioning in section
6. Startup.
15. If you installed a new dosing head with pressure
sensor, perform sensor calibration. See section
7.9.2 Calibration of pressure sensor.
If the diaphragm is possibly damaged,
don't connect the pump to the power
supply! Proceed as described in section
8.6 Diaphragm leakage.
Tighten the dosing head screws with a
torque wrench before startup and every
time the dosing head has been opened.
After 48 operating hours, retighten the
dosing head screws using a torque
wrench. Torque [Nm]: 6 (+ 1).
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