Pump Installation; Installation; Rotation Direction; Hydraulic Connections - Pratissoli LK Serie Manual De Uso Y Mantenimiento

9

PUMP INSTALLATION

9.1

Installation

The pump must be fixed horizontally using the Ø19 drilled
support feet.
The base must be perfectly flat and rigid enough as not to
allow bending or misalignment on the pump coupling axis/
transmission due to torque transmitted during operation.
Two lifting eyebolts are mounted on the pump for easy
installation, as per the figure below.
The eyebolts are sized for lifting the pump only.
Therefore they must never be used for any
additional loads.
Replace the oil filler closing plug located on the
casing with the oil filler cap.
The oil filler cap must always be reachable, even
when the unit is assembled.
The pump shaft (PTO) should not be rigidly
connected to the propulsion unit.
The following types of transmission are
recommended:
- Flexible joint.
- Cardan-shaft (comply with manufacturer's Max.
recommended working angles).
9.2

Rotation direction

The rotation direction is indicated by an arrow located near
the drive shaft.
From a position facing the pump head, the rotation direction
will be as in Fig. 6.
LH SIDE
anticlockwise
The drive can be taken from either side of the pump.
The pump is generally supplied with the PTO shank on the
right-hand side (see Fig. 6).
To have the drive on the left-hand side you need to remove
the shaft end cover and fit it on the right-hand side of the
pump (see par. 2.1.1 of the Repair manual).
On the contrary, the tab must be removed from the right-hand
side and inserted onto the shank on the left-hand side.
9.3

Hydraulic connections

In order to isolate the system from vibrations produced by
the pump, it is advisable to make the first section of the duct
adjacent to the pump (both suction and outlet) with flexible
piping. The consistency of the suction section must be such as
to prevent deformations caused by vacuums produced by the
pump.
9.4

Pump supply

The LK pumps must always be installed with a suction head,
that is they must receive the water by gravity or by forced
feeding, but never draw it from a lower level.
The pumps are able to withstand minimum suction heads of
even 1 metre, however, for the best volumetric efficiency and
above all to avoid cavitation, the available positive suction
head (NPSH avail) measured at the suction flange in the head
must be equal to or greater than the values below.
NPSH (m)
r
For the greater displacements, LK50 LK55 LK60 pumps, forced
feeding by a booster pump is highly recommended in order to
avoid cavitation, considering the geometry of the hydraulics
and the considerable flow rates.
The booster pump must have at least twice the flow rate of
the rated flow rate of the plunger pump and a pressure of
between 2 and 3 bar.
These supply conditions must be observed at all operating
speeds.
The booster pump must always be started up
before the plunger pump.
It is advisable to install a pressure switch on the
supply line downstream of the filters protecting
the pump.
9.5

Suction line

For a smooth operation of the pump, the suction line should
have the following characteristics:
1. Minimum internal diameter as indicated in the graph in
par. 9.8 and in any case equal to or exceeding that of the
pump head.
Localised restrictions should be avoided
along the run of the duct, as these can cause
load losses resulting in cavitation. Avoid 90°
elbow bends, connections with other piping,
constrictions, counterslopes, inverted U- curves and
T-connections.
2. With a layout that is set in such a way to prevent
cavitation.
3. Completely airtight and constructed to ensure sealing
over time.
4. Prevent that pump stopping causes emptying, even
partial.
5. Do not use 3 or 4-way hydraulic fittings, adapters, swivel
joints, etc. as they could jeopardise pump performance.
6. Do not install Venturi tubes or injectors for detergent
suction.
RH SIDE
7. Avoid use of base valves or other types of unidirectional
clockwise
valves.
8. Do not recirculate by-pass valve discharge directly into
Fig. 6
suction.
9. Provide for proper guards inside the tank to prevent that
water flow from the bypass and the tank supply line can
create vortexes or turbulence near the pump supply pipe
port.
10. Make sure the suction line is thoroughly clean inside
before connecting it to the pump.
11. Install the pressure gauge for checking the booster
pressure near the plunger pump suction port and again
downstream from the filters.
30
LK36 LK40 LK45 LK50
4 4.5 5.5 6.5
LK55 LK60
7.5 8