4. Disconnect the power cable from the terminal box, re-
move the screws (70.18) with the nuts (70.19) and
re-
move the motor
away from the coupling (64.22)
(
fig.4a
).
For MXV(L) 25-32-40, MXV(L)4 25-32-40:
5. Remove the nuts (61.04) from the tiebolts (61.02).
6. Remove the lantern bracket (32.00), complete with
bearing (66.00) and coupling (64.22) from the shaft
(64.00) and from the external jacket (14.02).
Once the lantern bracket (32.00) has been removed, all
the internal parts can be extracted with the shaft (64.00)
from the external jacket (14.02).
7. Remove the upper cover (34.02) with the o-ring (14.20)
and then the delivery casing (20.00).
For MXV(L) 50-65-80, MXV(L)4 50-65-80:
5. Remove the screws (61.07) and
remove the lantern
bracket
(32.00), complete with bearing (66.00) and
coupling (64.22) from the upper cover (34.02) and from
the shaft (64.00).
6. Remove the nuts (61.04) and washers (61.03) from
the tiebolts (61.02).
7.
Remove the upper cover
(34.02) from the shaft
(64.00) and from the external jacket (14.02) - or with
the external jacket from the pump casing (14.00) -
with the aid of a mallet or lever, exercising pressure
in alternate operations, from diametrically opposite
positions.
Once the upper cover (34.02) has been removed, all
the internal parts can be extracted from the pump casing
(14.00).
9.1. Replacing the mechanical seal
Make sure the spring of the
new mechanical seal
is set
with the direction of the winding suitable for the direction of
rotation of the shaft.
Make sure that all parts with which the mechanical seal
comes into contact are perfectly clean and free from any
burr or cutting edges.
The seal rings in EPDM
(Ethylene-Propylene)
must
never come into contact with oil or grease
. To facilitate
the mounting of the mechanical seal, lubricate the shaft,
the seating of the stationary part and the seal rings with
clean water or any other lubricant compatible with the
material in which the seal rings are made.
Use every precaution so as not to damage the seal sur-
faces with blows or angular impact.
Only for MXV(L), MXV(L)4
Remove the mechanical seal (36.00), the rotating part
from the shaft (64.00), making sure the shaft is not
scratched, and then the fixed part from the upper cover
(34.02).
Push the rotating part as far as the shoulder ring (36.52)
on the shaft (64.00), without compressing the spring.
Check the length before and after insertion and raise the
rotating ring as far as the initial length (L1 in
fig.4
).
In this way, correct compression of the spring will be en-
sured when the fixed part is mounted and after the shaft
is locked in the coupling (L2 in
fig.5b
).
9.2. Replacing the ball bearing MXV(L), MXV(L)4
If the ball bearing (66.00) has to be replaced, use a 2RZ
C3-type, of the size marked on the ball bearing to be
replaced and containing grease lubricant suitable for the
operating temperature.
The size of the bearing depends on the size of the motor:
motor size
ball bearing
80
6206, 2RZ, C3
90
6207, 2RZ, C3
100-112
6208, 2RZ, C3
132
6310, 2RZ, C3
160-180
6313, 2RZ, C3
9.3. First-stage bearing and intermediate bearing
The
MXV 50-16
,
65-32
and
80-48
pumps have a bearing
sleeve (64.10) on the shaft (64.00) and a bearing in the
stage casing (25.03) behind the first impeller (according to
the order of suction).
Starting with the
MXV.. 25-212, MXV.. 32-412
e
MXV.. 40-
811, MXV 50-1611, MXV 65-3208
and
MXV 80-4806
units,
there is also an intermediate bearing (see
section 15.
).
If they are to be dismantled, first number the position of
each stage casing and the single spacer sleeves (see
lengths and positions of sleeves in
section 15.
) so as to
be able to remount the components correctly.
10. Remounting
To remount the components follow the dismantling proce-
dure in inverse order (see
section 9.
).
Check the state of the o-rings (14.20) and replace them
of they are damaged.
Make sure that the o-rings (14.20) are correctly inserted
on their seats on the pump casing (14.00) and upper cov-
er (34.02). Lubricate the seal rings with clean water or
any other compatible lubricant.
10.1. Tightening torque
Type
MXV-B
MXV...
MXV...
25-32-40-50 25-32-40
50-65-80
impeller nuts (28.04)
8 Nm
8 Nm
35 Nm
nuts (61.04) on tie-bolts
50 Nm
50 Nm
50 Nm
screws (61.07) lantern upp. cov
-
-
60 Nm
screws (64.25) in the coupling
-
22 Nm
50 Nm
screws (70.18) with nuts (70.19)
-
40 Nm
40 Nm
When tightening the nuts (28.04),
be careful not to
scratch the shaft
with the second wrench used on the
opposite side.
ATTENTION: the nuts (61.04) on the tie-bolts (61.02),
the screws (61.07) on the upper cover and the
screws (70.18) with the nuts (70.19) on the lantern
bracket must be uniformly tightened with alternated
crossover tightening procedure in diametrically op-
posite positions.
64.00
36.00
Parte
14.20
14.02
36.52
34.02
L1
rotante
fissa
Parte
36.00
4.93.226/1
Fig.4 Inserting the mechanical seal
(*)
64.22
64.25
L2
64.00
4.93.226/2
Fig. 5a
Rotor rested, with shaft not
locked in the coupling.
(*) Pin for raising the shaft.
Fig. 5b
Rotor raised, position for locking
the shaft in the coupling.
Rotating
part
Fixed
part
15
