Version Change; Hydraulic Connections; Pump Supply; Suction Line - Interpump Group Sws71 Manuel D'utilisation Et D'entretien

9.3

Version change

The pump version is defined as right when:
Observing the pump facing the head side, the pump shaft
must have a PTO shank on the right side.
The pump version is defined as left when:
Observing the pump facing the head side, the pump shaft
must have a PTO shank on the left side.
Note. The version shown in Fig. 5 is right.
The version can only be modified by trained and
authorized personnel and carefully following the
instructions below:
1. Separate the hydraulic part from the mechanical
part as indicated in the chapter 2 par. 2.2.3 of the
Repair manual.
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. Connect the hydraulic part to the mechanical
part as indicated in the chapter 2 par. 2.2.5 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 meters is required for the best
volumetric efficiency with the fluid at ambient temperature
(see par. 9.6).
While with the fluid at high temperature max. 85°C, observe
the diagram below Fig. 6 that defines the minimum supply
pressures according to the different temperatures.
bar
psi
3,0
44
36 2,5
2,0
29
22 1,5
1,0
14
7 0,5
0,0
0
45 50 55
°C 40
°F 104 113 122 131 140
TEMPERATURA ACQUA [ °C - °F]
For negative prevalence contact our Technical
Office or Customer Service Departments.
60 65 70 75 80 85
149 158 167 176 185
Fig. 6
9.6

Suction line

For smooth operation of the pump, the suction line must have
the following characteristics:
1. Minimum inside diameter as indicated in the graph in par.
9.9 and in any case greater than or equal to the diameter
at the pump manifold.
Localized 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 made so as to ensure a minimum
positive head under all operating conditions of 0.2 m
(0.02 bar) measured on the pump supply; this value
applies for cold water with temperature up to 40°C. For
higher temperatures, the minimum positive head must be
obtained from the specific graph (par. 9.5).
The maximum positive head must not exceed 25m
(2.5 bar) measured at the pump inlet for water up to
a temperature of 75 °C. Above this temperature, the
maximum positive head must not exceed 35m (3.5 bar).
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 jeopardize pump performance.
6. Do not install Venturi tubes or injectors for detergent
suction.
7. Avoid use of foot valves or other types of unidirectional
valves.
8. Do not recirculate the by-pass valve drain directly to the
suction line.
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.
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