Outlet Line; Calculation Of The Internal Diameter Of The Duct Pipes; V-Belt Transmission - Pratissoli WK Série Manuel D'utilisation Et D'entretien

The filter must be installed as close as possible to the pump,
it must be easily inspected and must have the following
characteristics:
1. Minimum flow rate at least 3 times the nominal flow rate
of the pump.
2. Inlet/outlet port diameters no smaller than the inlet port
diameter of the pump.
3. Filtration grade between 200 and 360 µm.
For smooth pump operation, regular filter
cleaning is necessary, planned according to the
actual use of the pump in relation to the quality
of water used and actual clogging conditions.
9.8

Outlet line

For the correct laying of the outlet line, the following
installation rules must be followed:
1. The internal diameter of the pipe must be sufficient to
ensure correct fluid velocity, see graph in par. 9.9.
2. The first section of the line connected to the pump outlet
must be a flexible hose, in order to isolate the vibrations
produced by the pump of the rest of the system.
3. Use high pressure pipes and fittings to ensure high safety
margins in all operating conditions.
4. The outlet line must always be provided with a Max.
pressure valve.
5. Use pressure gauges suitable to withstand pulsating loads
typical of the plunger pumps.
6. During the design stage, keep in mind the line load losses
which result in a drop in pressure during use with respect
to the pressure measured on the pump.
7. 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.
9.9 Calculation of the internal diameter of the
duct pipes
To determine the internal diameter of the duct, refer to the
following diagram:
Suction duct
With a flow rate of ~ 170 l/min and a water velocity of 0.5 m/sec.
The graph line joining the two scales meets the central scale
showing the diameters, corresponding to a value of ~ 80 mm.
Outlet duct
With a flow rate of ~ 170 l/min and a water velocity of 5.5 m/sec.
The graph line joining the two scales meets the central scale
showing the diameters, corresponding to a value of ~ 30 mm.
Optimal speeds:
- Suction: ≤ 0.5 m/sec.
- Outlet: ≤ 5.5 m/sec.
The graph does not take into account pipe
resistance, valves, load loss produced by the length
of the ducts, the viscosity of the liquid pumped or
the temperature itself.
If necessary, contact our Technical or Customer
Service Departments.
9.10

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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