VARISCO DUO JD Instrucciones Para Su Utilizacion Y Mantenimiento página 24

Problem
13.3 Pump does not deliver enough
liquid
13.4 Pump does not provide enough
pressure
13.5 Pump absorbs too much power
13.6 Pump vibrates and is noisy
13.7 Pump jams
13.8 Bearings do not last
13.9 Seal leaks
13.10 Seal overheats
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INSTRUCTIONS FOR THE USE AND MAINTENANCE - DUO JD
Air leaks in suction line
Impeller and/or wear plate may be worn
Diameter of the suction pipe too small
Viscosity of the liquid is higher than
expected
Rotation speed too high
Pump operates under conditions that
contract
Density of the liquid is higher than planned
There may be friction inside the pump between
rotating and non-rotating components
Foreign matter in the impeller
too low
Pump cavitates
Foreign matter in the impeller
Foreign matter in bearings
Foreign matter in the impeller
Bearings are rusted
1-2 seal
The pump does not prime
Cause
This type of seal is suitable for
Remedy
Check joints are airtight and inspect
suction pipe
Replace them by disassembling
the pump as described in sections
10.2 and 10.3.
Replace suction pipe. Refer to
section 13.2 for other possible
causes.
Contact the pump manufacturer
once you have measured the
viscosity of the liquid.
Viscosity for centrifugal pumps
should not exceed 50 cSt.Check
for other possible causes: see point
5 in section 13.1, and section 13.2
Check correct rotation speed
Check operating conditions of pump
and compare them to those on the
pump's nameplate
Measure density of the liquid and
compare it with the agreed value
Disassemble pump casing as
indicated in sect. 10.2 and check
for scratches on surfaces
Disassemble pump casing as
described in section 10.2 and
remove foreign matter
Check settings of the valves in
the system and readings on the
pressure and vacuum gauges
Make sure system pipework is
correctly fastened
Check possible causes: see section
13.1 and 13.2
Disassemble pump casing as
described in section 10.2 and
remove foreign matter
Inspect impeller, disassem-bling
the pump casing as indicated in
section 10.2
Replace bearings
Replace bearings
pumping dirty liquids or liquids
containing abrasive particles and
petroleum products with temperatures
up to 110°C: check level of grease
in lubricator at regular intervals. If
well lubricated, it can run dry for 2
minutes. If the pump leaks during
operation, the seal must be replaced
(see section 10.4)
See section 13.1 and 13.9