11. Maintenance
Dosing pumps are produced according to the highest quality standards and have a long service life. Nev-
ertheless some parts are subject to wear caused by operation (e.g. diaphragm, valve seats, valve balls). To
ensure a long operating life, visual inspections are recommended regularly. Periodic maintenance protects
the dosing pump and system from unexpected downtime. The manufacturer recommends an annual main-
tenance if local valid regulations do not stipulate more frequent maintenance.
NOTICE!
Before working on the dosing head, valves and connections, flush the dosing pump with a harmless medium
(mainly water) to avoid unintentional contact with the metered medium.
NOTICE!
After replacing the diaphragm or other spare parts it might become necessary to gauged in litres, readjust
or calibrate (stroke frequency) the dosing pump.
11.1 Replacing the diaphragm
CAUTION!
Chemical could spray out. This may lead to caustic or other burns. The dosing pump head must always be
depressurized and rinsed thoroughly with water or a suitable medium before starting any work on the dosing
pump.
a
b
Replacing the diaphragm
IMPORTANT!
Do not continue before having disconnected the power supply of the pump.
Remove the dosing head
a
by loosening the four dosing head screws with a suitable tool
(Allen wrench SW 3).
Bend the diaphragm edge
b
slightly up, grip it with pliers and unscrew it anticlockwise.
IMPORTANT!
The diaphragm section of the dosing pump must be cleaned to remove any chemical before fitting a new
diaphragm, otherwise the diaphragm may be attacked from the rear.
Apply some grease (for example Molykote Longterm W2) to the thread of the new diaphragm. The new
diaphragm is turned clockwise manually until it sits close in the diaphragm rod.
Fit the dosing head at the front. Insert all four dosing head screws and tighten them lightly. After this tighten
the screws alternately, e.g. top left – bottom right – top right – bottom left. A tightening torque of 180 Ncm
is required for the dosing head screws.
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| Operation & Maintenance Instructions | Maintenance
