Dismantling; Maintenance, Servicing; Mechanical Seals; Lubrication Of Bearing - Xylem MPVN Manual De La Instrucción

between the test drives depend on the unit, but they
should be made at least once a week.

4.8 Dismantling

The operator's or manufacturer's fitters
should be informed as to the nature of the
liquid handled. In the case of pumps handling
dangerous liquids, the liquid handled should be
disposed of by environmentally acceptable means before
the pump is dismantled.
• Before starting to disassemble the pump unit make sure
that it cannot be switched on again.
• The pump casing must be depressurized and empty.
• All valves in the suction, intake and discharge pipes
must be closed.
• All components must have cooled down to ambient
temperature.
• To avoid corrosion it is recommended to flush the
pump and fill it with a water-repellant preservative,
e.g. KLÜBERTOP K01.601 or equal.
• To spread the preservative turn the pump several times
with the hand. Then drain the pump and lock the
nozzles.

5. MAINTENANCE, SERVICING

Work should only be carried out on the pump
or pump unit when it is not in operation. You
must observe Point 1.4 "Safety Instructions".
ATTENTION: MAINTENANCE AND SERVICING
WORK MUST ONLY BE CARRIED
OUT BY TRAINED, EXPERIENCED
STAFF WHO ARE FAMILIAR WITH
THE CONTENTS OF THESE
OPERATING INSTRUCTIONS, OR BY
THE DISTRIBUTOR'S OWN SERVICE
STAFF. THE WORK CARRIED OUT
MUST BE DULY ENTERED IN THE
"LOG BOOK" (SEE POINT 11) AND
CONFIRMED BY BEING SIGNED.

Mechanical Seals

Before opening the pump, it is essential that
you note Point 1.4 "Safety Instructions", Point
4.8 "Dismantling" and Point 8 "Repairs".
Mechanical seals do not need to be maintained and
are completely free of leakage. Pumps with mechanical
seals must only be operated when completely filled and
without air locks (or air pockets). The seal casing where
the mechanical seal is located must always be filled with
the sealing liquid. If the liquid being handled drips out at
the mechanical seal, it is damaged and must be replaced.
When installing the mechanical seal, make sure that
the seal cavity is absolutely clean, particular care has to
be paid to the surface of the seal rings. To facilitate the
slip-on of the rotating components of the seal onto the
shaft, lubricate all moving components and sliding areas
by means of water, soapy water or soft soap. Use mineral
oils only in case all elastomers are oil resistant. Do not
lubricate the surface of the seal rings. Do not force
elastomeric elements over sharp edges, if necessary use
assembling aiding sleeves.

Lubrication of Bearing

• Intervals of re-lubrication/grease quantities (see point
2.3 "bearing and lubrication").
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• If the pump is left non-operational for any length of
time, the grease in the bearings should be changed
after 2 years.

Coupling

When inspecting the element, look for fatigue cracks
(over ½") originating near the stress relief grooves
(approximately ¼" – ½" above the metal shoe),
discoloration (a darker faded orange color signals
possible material degradation) or surface cracking if used
in adverse conditions such as cooling towers or severe
environments (pH < 4 or pH > 10).
In critical applications, the probability of unexpected
downtime can be greatly diminished by scheduling
flexible element replacement at regular intervals. The
frequency of replacement will depend upon the severity
of the application and environmental conditions. A
properly sized element which is stored and operated
under normal conditions (i.e. under 85% humidity and
85°F) should obtain a minimum of 6 to 8 years of service
life after the date of manufacture. A production date
sticker is applied to all elements for ease of inspection
(I.E. 3Q93 indicates Third Quarter 1993 production).
After the coupling has been in operation for some time,
a "torsional set" may develop in the flex element (up to
⁄ " on a size E40, even more on larger sizes). This does
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not affect the performance of the coupling, as it is simply
the material creeping under the applied stress. A very
large torsional set may suggest a sizing problem and will
warrant a close review of the application and coupling
selection parameters. For ease of assembly/disassembly,
elements should be re-installed in the same "position of
rotation" in which they were removed.
INSPECT
HERE

Cleaning the Pump

Dirt on the outside of the pump has an adverse effect
on transmission of heat. The pump should therefore be
cleaned with water at regular intervals (depending on the
degree of dirt).
ATTENTION: THE PUMP SHOULD NOT BE
CLEANED WITH PRESSURIZED
WATER – WATER WILL GET INTO
THE BEARINGS AND INTO THE
MOTOR.

6. LONGER PERIODS OF NON-OPERATION

6.1 Drained Pumps

• Turn by hand at least 1 x week (do not switch on because
of dry running).
• If necessary, unblock by tapping gently on the coupling in
axial direction.
• Change the grease in the bearings after 2 years.
• Replace bearings after 5 years.

6.2 Filled Pumps

• Switch stand-by pumps on and immediately off again
once a week.
• If the stand-by pump is at operating pressure and
temperature:
• Change the grease in the bearings after 2 years.
• Replace bearings after 5 years.