Hydraulic Connections; Pump Supply; Suction Line; Outlet Line - Pratissoli KF5M Serie Betriebs- Und Wartungsanleitung

2. Turn the mechanical part 180° and reposition
the rear casing cover in such a way that the
oil dipstick is turned upward. Reposition the
lifting bracket and relative hole closing plugs
in the upper part of the casing. Finally, properly
reposition the specification label in its housing
on the casing.
Make sure that the lower casing draining
holes in correspondence with the pistons are
open and not closed from the plastic plugs
provided for the previous version.
3. Unite the hydraulic part to the mechanical part
as indicated in chapter 2 par. 2.2 of the Repair
manual.
9.4

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 suction hose must be sufficiently rigid to prevent
deformation due to the negative pressure exerted by the
action of the pump.
9.5

Pump supply

A positive head of at least 0.20 metres is required for the best
volumetric efficiency, to be increased with increasing fluid
density.
For the priming conditions see the chart in
par. 9.8.
9.6

Suction line

For smooth operation of the pump, the suction line must have
the following characteristics:
1. Minimum internal diameter for pipes of length less than
8 m. 1"1/2.
The pipe must be rigid enough to avoid self‑constriction
caused by the pressure drop.
Localised restrictions should be avoided along the
piping, as these can cause pressure drops resulting
in cavitation. Avoid 90° elbows, connections with
other piping, restrictions, reverse gradients, inverted
U‑curves and Tee connections.
2. The layout must be such as to prevent cavitation
problems.
3. Completely airtight and constructed to ensure a perfectly
hermetic seal through time.
4. Prevent the pump from emptying when it is stopped,
including partial emptying.
5. Do not use 3 or 4‑way hydraulic fittings, adapters, swivel
joints, etc. as they could jeopardies pump performance
due to excessive head losses.
6. Avoid use of foot valves or other types of unidirectional
valves.
7. Do not recirculate the by‑pass valve drain directly to the
suction line.
8. Provide for proper guards inside the tank to prevent that
bentonite flow from the bypass and the tank supply line
can create vortexes or turbulence near the pump supply
pipe port.
9. Make sure the suction line is thoroughly clean inside
before connecting it to the pump.
9.7

Outlet line

For correct design of the outlet line comply with the following
installation prescriptions:
1. The internal diameter of the pipe must be sufficient to
ensure correct fluid velocity.
2. The first section of the line connected to the pump outlet
must be a flexible hose, in order to isolate vibration
produced by the pump from the rest of the system.
3. Use high pressure pipes and fittings to ensure high safety
margins in all operating conditions.
4. Use pressure gauges capable of withstanding the
pulsating loads typical of plunger pumps.
5. During the design stage, keep in mind the line pressure
drops that lead to a pressure reduction at the user with
respect to the pressure measured on the pump.
6. For those applications where pulses produced by the
pump on the outlet line may prove harmful or unwanted,
install a pulsation dampener of sufficient size.
9.8

Typical Diagram

9.9 V‑belt transmission
The pump can be controlled by a V‑belt system.
For this pump model, we recommend use of 4 XPB belts
(16.5x13 serrated). Use an XPC profile only for long durations.
Both the characteristics and transmissible power of each
belt can be verified in the diagram in Fig. 7, in relation to the
number of rpm normally declared by the manufacturer.
Minimum duct pulley diameter (on pump shaft): ≥ 250 mm.
The radial load on the shaft must not exceed 7500 N
(value necessary for Layout definition). The transmission is
considered adequate if the load is applied to a maximum
distance a=40 mm from the shaft shoulder (P.T.O) as shown in
Fig. 10.
For dimensions differing from those specified
above, contact our Technical or Customer Service
Departments.
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Fig. 6