Grundfos DME 2 Notice D'installation Et D'entretien page 29

9. Fault finding chart
Fault
The dosing has
stopped or the output
is too low.
Pump dosing too little
or too much.
Pump dosing irregu-
larly.
Leakage from drain
hole.
Frequent diaphragm
failures.
10. Disposal
Disposal of this product or parts of it must be carried
out according to the following guidelines:
1. Use the local public or private waste collection
service.
2. In case such waste collection service does not
exist or cannot handle the materials used in the
product, please deliver the product or any haz-
ardous materials from it to your nearest Grundfos
company or service workshop.
Cause
Valves leaking or blocked.
Valves incorrectly installed.
Suction valve or suction pipe/hose
leaking or blocked.
Suction lift too high.
Viscosity too high.
Pump out of calibration.
Pump out of calibration.
Valves leaking or blocked.
Diaphragm defective.
Diaphragm not fastened properly.
Counter-pressure too high (meas-
ured at the pump discharge port).
Sediment in dosing head.
Remedy
Check and clean valves.
Remove and fit valves. Check that the arrow
on the valve casing is pointing in the liquid
flow direction. Check that all O-rings have
been fitted correctly.
Clean and seal the suction pipe/hose.
Install the pump in a lower position.
Install a priming tank.
Select the anti-cavitation function, see sec-
tion 4.14.
Install a pipe/hose with larger cross-section.
Fit spring-loaded valves.
Calibrate the pump, see section 6.
Calibrate the pump, see section 6.
Check and clean the valves.
Install a new diaphragm.
Install a new diaphragm and ensure that the
diaphragm is fastened properly.
Check the system. Check the injection valve,
if required. Reduce the dosing stroke by fitting
a pulsation dampener.
Clean/flush the dosing head.
Subject to alterations.
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