Inspection; How To Remove The Pump; Inspection Of Seal Sensor; Inspection Of Impeller And Wear Plate - Grundfos DPK.10.50.075 Installation And Operating Instructions Manual

14.2 Inspection

Under normal operating conditions, remove the
pump from the tank and inspect it once every year.
Under severe operating conditions where sand,
fibrous material and solids are involved, do this once
a month.
The standard inspection procedure is summarized
below.

14.2.1 How to remove the pump

1. Hook the lifting chain through the pump lifting
bracket and lift so that the chain just carries the
load of the pump.
2. Loosen the bolts/nuts of the discharge pipe to
drain away possible water in the pipe.
3. Remove the bolts/nuts of the discharge pipe, and
lift the pump out of the tank.

14.2.2 Inspection of seal sensor

Check the resistance of the seal sensor with a
multimeter as shown in fig. 12.
Do not use a megger as this will
Caution
damage the control circuit.
TP TP
SS SS
Fig. 12 Resistance check
Oil replacement
After checking the resistance of the seal sensor,
replace the oil in the oil chamber.
1. Unscrew the oil screw.
2. Tilt the pump with the oil filling hole pointing
downwards in order to drain the pump of oil. If the
drained oil is contaminated or opaque, this is an
indication of an impending mechanical shaft seal
failure. Replace the mechanical seal.
3. Fill fresh oil into the oil chamber through the oil
filling hole. Use lubrication oil ISO VG 32 Mobil
DTE 24 turbine oil 90 or equivalent.

14.2.3 Inspection of impeller and wear plate

Check the clearance between impeller and wear
plate. Recommended clearance is 0.3 - 0.5 mm.
Replace or repair as necessary.

14.3 Overhaul

Overhaul of pumps should be carried out by an
authorized Grundfos service workshop.
A normal overhaul includes these points:
1. Disassemble and clean the pump.
2. Inspect and replace, if necessay, each
3. Carry out electrical test of the motor.
4. Replace worn-out or damaged components.
5. Reassemble the pump.
6. Carry out performance and functional test of the
7. Repaint and pack the pump.
20 KΩ
component.
pump.
13