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MXV, MXV-B Rev6 - Operating Instructions
Page 19 / 136
MXV(L) 50-65-80, MXV(L)4 50-65-80
In the case of vertical installation, remove the plug (2)
during the filling operation to vent the suction side.
After the liquid has been released, replace the plug
(2). Proceed with filling until the liquid spills out of the
venting hole (1 ) in the upper cover. Top up until the
pump is completely vented before replacing the plugs
(1). In the case of horizontal installation, fill and vent
through the holes (1) in the pump casing (14.00).
MXV.. 50-65-80
(3)
(1) (2)
(2)
(1)
(3)
(3)
Fig 3 : (1) Riempimento e sfiato
(2) Sfiato aspirazione
(3) Scarico
4.93.215
Fig.4 (1) Filling and air vent
(2) Suction side air vent
(3) Draining
When the liquid level on the suction side is above
the pump
(inflow under positive suction head,
fig.
3B
), fill the pump by slowly and completely opening
the inflow gate valve while keeping the delivery gate
valve and air vent holes (1), (2) (
fig.4
) open to release
the air.
During filling, keep the air vent holes (1)(2)
open only if the inflowing liquid presents no
possible danger on account of its nature,
temperature or pressure.
Only for MXV(L)50-65-80, MXV(L)4 50-65-80, If
necessary, install joints with a tap/valve device to
holes 1 and 2, to control the outflow of the liquid and
its direction of flow.
With a delivery pipe arranged horizontally, or lower
than the pump, keep the delivery gate valve closed
during the filling operation.
7.3. Starting and checking operations
Close the air vent holes (1), (2) (fig.4), for MXV-B,
MXV(L) 25-32-40 e MXV(L)4 25-32-40 Tighten the
needle screw (14.17) in the drainage plug (14.12) (fig.
4b) and close the air vent hole (14.04).
Start the pump with the delivery gate valve closed and
with the suction gate valve fully open. Immediately
afterwards, gradually open the delivery gate valve,
adjusting the point of operation within the limits
indicated on the name plate.
When starting, with a three-phase motor, check if
the direction of rotation is as shown by the arrows
on the lantern bracket.
Otherwise disconnect
electrical power and reverse the connections of two
phases.
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, repeat the venting
operation on the suction side (2), make sure all the
suction pipe couplings are perfectly sealed and tighten
the air vent plug (2) and the draining plugs (3) on the
suction side (
fig.4
).
ATTENTION: when the pump is located above the
water level
(suction lift operation,
fig. 3A
),
after a
long idle period, 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.
3
) to ensure a
minimum flow
of about:
0,3 m
3
/h for MXV(B) 25, MXV(L) 25, MXV(L)4 25,
0,4 m
3
/h for MXV(B) 32, MXV(L) 32, MXV(L)4 32,
0,5 m
3
/h for MXV(B) 40, MXV(L) 40, MXV(L)4 40,
1,0 m
3
/h for MXV-B 50, MXV(L) 50, MXV(L)4 50
1,5 m
3
/h for MXV(L) 65, MXV(L)4 65
2,6 m
3
/h for MXV(L) 80, MXV(L)4 80
2,9 m
3
/h for MXV(L) 100
When the w
ater 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.
7.4. Switch off of the pump
ON
The appliance must be switch off every time
there are faults. (see troubleshooting).
The product is designed for a continuous duty, the
switch off is performed by disconnecting the power
supply by means the expected disconnecting devices.
(see paragraph “6.5 Electrical connection”).
8. MAINTENANCE
Before any operations it's necessary to disconnect the
power supply.
If required ask to an electrician or to an expert
technician.
Every maintenance operations, cleaning or
reparation executed with the electrical system
under voltage, it could cause serious injuries
to people.
If the supply cord is damaged, it must be
replaced by the manufacturer, its service agent
or similarly qualified persons in order to avoid
a hazard.
In case of extraordinary maintenance, or maintenance
operations that require part-removing, the operator
must be a qualified technician able to read schemes
and drawings.
MXV, MXV-B Rev6.indd 19
01/10/18 17:06
