Xylem MPV - Manual (Page 93)

Installation, Operating and Maintenance Instruction
Model MPB, MPV
MPB 100-english page 89 Revision 02
Article No 771074115 Issue 01/2010
the stationary part for this purpose (see sectional
drawing).
Loosen the nuts (M3) and screws (S9), the
cartridge mechanical seal (GLRD) should move
freely.
Disassemble the pump as described in Section
8.5.2 "Replacing the Rolling Bearing – MPV
Design" Disassembly.
Remove the bearing cover (12), spacer sleeve
(72) and thrower (73P).
Pull off the cartridge seal (without shaft wearing
sleeve (44)).
Pull out the key (PF3) and pull off the shaft
wearing sleeve (44). Remove the O-ring (OR4).
Clean all parts well and check for wear. In
principle, mechanical seals must be replaced.
Repair of the mechanical seal is only
recommended if performed by an expert. Worn
parts of the cartridge seal can be replaced or
repaired by the manufacturer.
Assembly
Always use a lubricant when assembling the
mechanical seal (e.g. silicone grease). Please do
not use mineral grease or oil if the O-ring is not
resistant to such materials.
Slide on the O-ring (OR4) and coat with lubricant
(e.g. silicone grease) using a small brush.
Lubricate the shaft protective sleeve (44) in the
borehole) so that the O-ring groove remains clean
(start approx. 10-15mm inside). Standard O-rings
made of EP rubber are not resistant to oil
emulsive lubricants and must not come into
contact with them. Once resistance has been
ensured (e.g. beef dripping as lubricating agent or
oil resistant O-rings) the entire shaft (24) may be
lubricated.
Slide on the shaft wearing sleeve (44), making
certain that the O-ring can slip lightly into the
groove.
Slide on the cartridge mechanical seal (GLRD) but
do not yet screw it tight (M3 and S9 remain loose).
Insert the key (PF3) and slide on the spacer
sleeve (72). The following assembly direction must
be observed.
MPV 100 MPV 125
44 72 44 72
Slide on the thrower (73) and bearing cover (12)
Continue the assembly as described in Section
8.5.2 "Replacing the Rolling Bearing – MPV
Design" .. Assembly
Finally, tighten the nuts (M3) then the screws (S9)
(observe this order). Put the locking clip (FB) into
its initial position.
Turn the shaft (24) and check for easy motion.
8.8 Dismantling
See "Appendix" in the Operating Instructions for
sectional drawing
If the entire pump is being disassembled for
maintenance work, the pump should be placed
vertically on the motor stool (11, MPB design) or on
the bearing pedestal (8, MPV design) (suction casing
facing upward).
MPB Design Only: Remove the motor as described
in Section 8.5.1 "Replacing the Rolling Bearing – MPB
Design" Disassembly.
For the designs MPB40, MPB65, MPB100, MPV100
and MPV125, a lifting device or a second person are
required for disassembly.
Secure the pump against tipping.
This description does not include disassembly
of the mechanical seal. Read the entire
instructions for "Replacing the Shaft Seal"
before disassembling the pump so that any
preliminary work required can be performed
appropriately.
Screw off the nuts (M1), remove the casing
screws (25)
Remove the suction casing (3), take out the O-ring
(OR1).
Screw off the impeller nuts (28), remove the
washer (29)
Pull off the bearing sleeve (23).
Remove the impeller (1) and diffuser (2), take out
the key (PF1). Label all parts for reassembly.
Disassemble the pump in stages up to the
pressure casing
Turn the remaining portion of the pump (motor
stool (11) or bearing pedestal (8) facing upward),
axially affix the shaft (24) (secure it so that it
cannot slide off).
Removal of the shaft seal: see Section 8.7
"Replacing the Shaft Wearing Sleeve with the
Packing Gland / Replacing the Shaft Seal" and the
corresponding subsection.
Clean all parts well. If the assembly is to be
performed at a later time, carefully store the pump
parts and protect them against corrosion.
8.9 Repairs
Clean all parts and check for wear. In case of
excessive wear, parts must be replaced. This is a
practical opportunity to renew parts such as seals (O-
rings), roller bearings and shaft seals.