7. STARTUP AND OPERATION
7.1. Preliminary checks before start-up of the
pump
Do not start-up the device in case of damaged parts.
Make sure the coupling with the pump shaft turns
freely when rotated by hand (see section 6.5.).
Make sure the screws (64.25) of the coupling are
tightened (see section 9.2.).
Make sure the coupling guard (32.30) is
fastened on the lantern bracket.
For MXV-B Make sure the shaft turns freely when
rotated by hand.
For this purpose use the screwdriver notch on the shaft
end ventilation side.
7.2. Filling
OFF
ATTENTION: never run the pump dry, not even for a
short trial run.
Start the pump after filling it completely with liquid.
When the pump is located above the water level
(suction lift operation, fig. 3A) or with a positive suction
head which is too low (less than 1 m) to open the non-
return valve, fill the suction pipe and the pump through
the priming hole (1) (fig. 4).
To facilitate this operation use a flexible tube (or elbow)
and a funnel.
MXV-B, MXV(L) 25-32-48, MXV(L)4 25-32-48
During filling, the needle screw (14.17) in the drainage
plug (14.12) must be kept loose so as to allow a free
passage between the pressure chamber and the
suction chamber (Fig.4a).
MXV-B, MXV 25-32-48
Filling and
air vent 14.04
(1)
Fig. 4a Filling:
internal passage open
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, MXV-B Rev4 - Operating Instructions
4.93.008
Fig. 4c Drainage
14.12
14.17
4.93.306
Fig. 4b Operating:
internal passage closed
MXV.. 50-65-80
(1)
(2)
(3)
(3)
Fig.4 (1) Filling and air vent
(2) Suction side air vent
Fig 3 : (1) Riempimento e sfiato
(3) Draining
(2) Sfiato aspirazione
(3) Scarico
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.
Check that the direction of rotation is as shown
by the arrow: i.e. counter-clockwise when
viewing the motor from the fan end for MXV-B 50,
MXV(L)50-65-80, MXV(L)4 50-65-80, i.e. clockwise
when viewing the motor from the fan end for
MXV-B 25-32-40, MXV(L) 25-32-40 e MXV(L)4 25-
32-40; 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).
(1) (2)
4.93.215
(3)
Page 19 / 136
GB