22 | Operation Manual MIDIDOS E | Maintenance
11.3 Replacing the diaphragm
CAUTION!
Chemicals may spray out this may lead to caustic or other burns. The dosing pump head
must always be depressurized and rinsed with water or another suitable medium before
starting any work on the dosing pump.
Legend
a
Dosing head
b
Diaphragm
c
Supporting plate
(with MIDIDOS E 24, 48 and 72)
d
Diaphragm chamber
f
Diaphragm insert
g
Motor
Fig. 1
Fig. 2
a
b
c
d
f
g
1
2
3
4
6
7
CAUTION!
Changing the diaphragm
1. Remove the dosing head
a
with a suitable
tool (Allen key SW 10 or. SW13 for E120).
(see Fig. 1)
2. The dosing pump is set whilst the motor
is running at zero-capacity, whereby the
diaphragm
b
is secured into its stop position.
3. Turn the pumps off.
4. Diaphragm
b
, take its edge and turn it anti-
clockwise. So that the supporting plate
c
behind the diaphragm is also moved.
(see Fig.2)
IMPORTANT!
The supporting plate
c
must be cleaned from
chemicals before a new diaphragm is built in,
otherwise the diaphragm can be attacked from
the rear.
IMPORTANT!
