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9.1. Replacing the mechanical seal
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).
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: i.e. counter-clockwise when seen from the stationary ring.
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. 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.5
).
In this way, correct compression of the spring will be ensured
when the fixed part is mounted and after the shaft is locked in
the coupling (L2 in
fig.6b
).
Use every precaution so as not to damage the seal surfaces
with blows or angular impact.
9.2. Replacing the ball bearing
If the ball bearing (66.00) has to be replaced, use a 2Z 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
100-112
6208, 2Z, C3
132
6310, 2Z, C3
160-180
6313, 2Z, 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 50-1611, MXV 65-3208
and
MXV 80-4806
units, there is also an intermediate bearing (see
section 13.1.
).
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 13.2.
) so as to be able to re-
mount the components correctly.
10. Remounting
To remount the components follow the dismantling procedure 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 cover (34.02). Lu-
bricate the seal rings with clean water or any other compatible
lubricant.
10.1. Tightening torque
impeller
nuts
screws (61.07) screws (64.25) screws (70.18)
nuts (28.04)
(61.04)
lantern -
in the
with nuts
on tie-bolts upp. cov.
coupling
(70.19)
35 Nm
50 Nm
60 Nm
50 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 opposite positions.
10.2. Axial position of the pump rotor
In the vertical position and from the resting position (
fig.6a
),
raise the rotor, levering on a pin inserted in the hole in the shaft,
until the pin can be rested under the coupling (64.22).
In this position (
fig. 6b
), by tightening the screws (64.25) uni-
formly, the shaft (64.00) is locked tight in the coupling.
Remove the pin.
Mount the motor as indicated in
section 4
.
11. Horizontal installation
11.1 Connection of support feet
For the mounting of the support feet all tour nuts (61.04) on the
tie-bolts (61.02) must be removed (see cross-section drawing in
section 13.
).
ATTENTiON: do not loosen only the two nuts
on the side of
the upper cover to which the support foot is to be attached.
To remove the 4 nuts (61.04) the lantern bracket (32.00)
must be removed.
With the pump in the vertical position, carry
out dismantling sequences 1 - 6 in
section 9
.
Remove the washers (61.03) and attach the support foot
(61.30) on the side of the upper cover (34.02) in the appropriate
position depending on the directional arrangement of the pump
casing (14.00) suitable for the system: suction on the left and
delivery on the right, or vice-versa (
fig.7
)
Do not insert the two washers (61.03) on the support foot when
the tie-bolts (61.02) do not protrude from the nuts (61.04).
The 4 nuts must be uniformly tightened with alternated
crossover tightening procedure in diametrically opposite
positions
. Tightening torque as per
section 10.1
.
Mount the lantern bracket (32.00) with the coupling (64.22) and
position the pump shaft as indicated in
section 10.2
.
Mount the motor as indicated in
section 4
, and orientate the
terminal board with respect to the support foot (61.30) in the
position most suitable for the system.
After setting the pump in the horizontal position, fix the second
support (61.30) to the base (61.00), with the screws (61.30),
washers (61.34) and nuts (61.36), and check for accurate
levelling of the installation with respect to the first foot.
12. Spare parts
When ordering spare parts please quote their designation, position
number in the cross section drawing (
section 13.
) and rated
data from the pump name plate (type, date and serial number).
Any
pumps that require inspection/repair
must be
drained and carefully cleaned inside and outside
before dispatch/submission.
Changes reserved.
64.00
36.00
Parte
14.20
14.02
36.52
34.02
L1
rotante
fissa
Parte
36.00
4.93.226/1
Fig.5 Inserting the mechanical seal
(*)
64.22
64.25
L2
64.00
4.93.226/2
Fig. 6a
Rotor rested, with shaft not
locked in the coupling.
(*) Pin for raising the shaft.
Fig. 6b
Rotor raised, position for locking
the shaft in the coupling.
Variation 1: suction on the left,
Variation 2: suction on the right,
delivery on the right
delivery on the left
Fig.7 Orientation of the ports in a horizontally-fitted pump
4.93.213/3
4.93.213/4
10
Rotating
part
Fixed
part