Model mp, mpa, mpai, Servicing, maintenance, 1 general remarks – Xylem MPAI User Manual
Page 89: 2 mechanical seals, 3 stuffing boxes, 4 lubrication and change of lubricant, 5 coupling

Installation, Operating and Maintenance Instruction
Model
MP, MPA, MPAI
MP 100-english
page 85
Revision 04
Article No 771074011
Issue 11/2011
7. Servicing, Maintenance
7.1 General remarks
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 Manufacturer's own
service staff.
Work should only be carried out on the pump or
pump unit when it is not in operation. You must
observe chapter 2.
7.2 Mechanical seals
Before opening the pump, it is essential that you
note chapter 2 and chapter 8.
If the liquid being handled leaks out at the mechanical
seal, it is damaged and must be replaced.
Replace the mechanical seal according to Section 8.6
"Replacing the Shaft Seal".
Mech. seals do not need to be maintained and are
completely free of leakage. Pumps with mech. seals
must only be operated when completely filled and
vented. The mechanical seal chamber must always
remain filled with liquid during operation of the pump.
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 casing 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.
7.3 Stuffing boxes
Stuffing boxes require constant maintenance, see
chapter 6.2 section "Stuffing box". If the leakage rate
can no longer be set correctly, the packing is worn out
and must be replaced in good time (increased wear on
shaft sleeve). Replace the packing gland according to
Section 8.7 "Replacing the Shaft Seal".
If employing new packing tight at the beginning the
gland only gentle (heavy leakage). Arrange ends of
packing rings at opposite positions (refer to drawing).
After a while tighten the gland smoothly until leakage
is reduced to only a few drops per minute. Avoid dry
run.
Method of opening packing rings to fit over shaft
Joints staggered correct incorrect
Because of the risk of accidents, addition of
packing to pumps during operation or at
operating pressure or temperature is strictly
forbidden!
7.4 Lubrication and Change of Lubricant
Re-greasing
Grease lubricated bearings with the possibility of
re-greasing must be re-lubricated all 4000
operating hours, but at least 1x year. Clean
lubricating nipples (G) first.
Lubricating grease quality ...
... K2K-20, KP2K-20, etc. as per DIN 51825:
-
Lithium soap grease
-
NLGI GRADE 2
-
Temperature range -20 to 120°C
-
Dripping point > 175°C
-
Base oil viscosity 70 to 150 mm²/s at 40°C
When changing the grease type, ensure
compatibility with the residual grease.
Quantity of re-greasing (approx. value)
Pump Size
Grease Quantity
Suction Side
Pressure Side
[cm
3
]
[cm
3
]
MP/MPA/MPAI 40.2
7,6
12,1
MP/MPA/MPAI 40.3
7,6
12,1
MP/MPA/MPAI 65.1
9,3
15,5
MP/MPA/MPAI 65.2
9,3
15,5
MP/MPA/MPAI 100.1
11,5
23,0
MP/MPA/MPAI 100.2
11,5
23,0
MP/MPA/MPAI 125.1
16,5
33,0
MP/MPA/MPAI 125.2
16,5
33,0
Pump Size
Relubrication Intervals in Operating
Hours
3550 2950 2200 1750 1450
[min
-1
] [min
-1
] [min
-1
] [min
-1
] [min
-1
]
MP/MPA/MPAI 40.2 3800 4300 5500 6000 6500
MP/MPA/MPAI 40.3 3800 4300 5500 6000 6500
MP/MPA/MPAI 65.1 3500 4000 5000 5500 6000
MP/MPA/MPAI 65.2 3500 4000 5000 5500 6000
MP/MPA/MPAI 100.1 3300 3800 4500 5000 5500
MP/MPA/MPAI 100.2 3300 3800 4500 5000 5500
MP/MPA/MPAI 125.1 2500 3300 4300 4800 5000
MP/MPA/MPAI 125.2 2500 3300 4300 4800 5000
Relubrication intervals with activation durations of
approx. 50% (cycle duration 1 hour).
For activation durations of approx. 100%, halve the
relubrication intervals.
If the pump is left non-operational for a longer
time, the grease in the bearings should be
changed after 2 years.
7.5 Coupling
Check the clearance in the coupling components
regularly approx. every 1000 operating hours, but at
least 1x year, the radial clearance in the coupling parts
must be checked.