Maintenance And Monitoring Pump Operation; Dismantling; Replacing The Mechanical Seal; Delivery Pipe - Calpeda MXV Instrucciones Originales De Uso

istr_MXV25 01_2010 10-12-2009
Check that the pump works within its field of performance and
that the absorbed current shown on the name-plate is not
exceeded. Otherwise adjust the delivery gate valve or the
setting of any pressure switches.
If a priming loss occurs (interruption of delivery flow, despite
opened gate valves) or if a pressure oscillation is indicated on
the pressure gauge, make sure all the suction pipe couplings
are perfectly sealed and tighten the needle screw in the
drainage plug (fig. 3b).
ATTENTION: when the pump is located above the water
level (suction lift operation,fig. 2A), after a long idle peri-
od, before restarting the unit, check that the pump is
still filled with liquid and vented.
Otherwise, check for proper operation (opening and closing) of
the foot valve and fill the pump with liquid (see section 7.2.).
Never run the pump for more than five minutes
with a closed gate valve.
Prolonged operation without a change of water in the pump
causes dangerous increases of temperature and pressure.
In systems in which it may be possible to operate with a closed
delivery gate valve, install a bypass valve (fig. 2) to ensure a
minimum flow of about: 0.3 m
MXV.. 32-4; 1 m 3 /h for MXV.. 40-8.
When the water is overheated due to prolonged operation with
a closed port, stop the pump before opening the gate valve.
To avoid any risk of danger to users and the creation of harmful
thermal stress in the pump and system due to large temperature
differentials, wait until the water has cooled inside the pump before
starting again or before opening the drainage and filling plugs.
Care must be taken when the pumped fluid has a
high temperature. Do not touch the fluid when its
temperature is higher than 60 ˚C. Do not touch the
pump or motor when their surface temperature is
higher than 80 ˚C.

8. Maintenance and monitoring pump operation

Under normal operating conditions the pump-motor unit will not
require maintenance.
Conduct routine inspection on the pump and connected parts to
check for a perfect seal.
Check the seal on the shaft from the outside through the
coupling guard.
The special funnel-shaped lantern bracket is designed to con-
tain any small initial leaks.
Keep the pump and surrounding part clean so as to be able to
immediately detect any outward leakage.
Clean the filter in the suction pipe and/or foot valve at regular
intervals; check performance and absorbed current.
The ball bearings in the motor and the ball bearing in the pump
(66.00 - see section 9.2) have permanent lubrication.
No regreasing is necessary.
See the operating instructions of the motor (if supplied).
Remove any excess grease expelled from the ball-bearing
(66.00) after the first period of operation.
In the case of water containing chloride (chlorine or sea water)
the risk of corrosion increases in stagnant water conditions
(also with an increase in temperature and decrease of pH
value). In these cases, if the pump remains inactive for long
periods, it must be emptied completely.
For good measure, as for temporary operation with dirty liquids,
run the pump briefly with clean water to remove deposits.
When the pump remains inactive it must be emptied
completely if there is a risk of freezing (fig.4).
Air inlet
Fig. 4 Drainage
8
8:23 Pagina 8
3 /h for MXV.. 25-2; 0.5 m 3 /h for
4.93.008
Before starting the motor again fill the pump completely with
liquid (see section 7.2.) and make sure the shaft is not jammed
by encrustation, sticking of the faces of the mechanical seal or
other causes. In the event that the shaft cannot be moved by
hand, the pump has to be dismantled and cleaned.
Disconnect electrical power before any servicing
operation and make sure the pump cannot be
accidentally switched on.

9. Dismantling

Before dismantling, close the gate valves in the suction and
delivery pipes and empty the pump casing (fig. 4).
For dismantling and re-assembly refer to the section drawing
(section 12.) and figures 5 and 6.
Dismantling and inspection of all internal parts can be carried
out without removing the pump casing (external jacket 14.02)
from the pipeline.
Sequence for dismantling:
1. Mark the position of the motor on the lantern bracket (32.00) and
the position of the lantern bracket on the external jacket (14.02).
2. Remove the screw (32.32) with the washer (32.31) and the
coupling guard (32.30).
3. Loosen the screws (64.25) of the coupling (64.22).
ATTENTION: to avoid compressing the spring of the mechanical
seal (36.00) because of axial shifting of the shaft (64.00), we
recommend to loosen the screws (64.25) of the coupling
(64.22) even only for removing or replacing the motor.
Afterward reposition the shaft (64.00) as indicated in section 10.2.
4. Disconnect the power cable from the terminal box, remove
the screws (70.18) with the nuts (70.19) and remove the
motor away from the coupling (64.22).
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).

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. clockwise when seen from the stationary ring.
64.00
Rotating part
Parte rotante
36.00
L1
Fig.5 Inserting the mechanical seal
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.
Fixed part
Parte fissa
36.00
32.00
14.20
34.02
36.52
14.02
3.93.018