Outlet Line; Calculation Of The Internal Diameter Of The Duct Pipes; V-Belt Transmission; Transmission Of Power From The Second Pto - Pratissoli MF Serie Manual De Uso

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 safety
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 ~ 400 l/min and a water velocity of 1 m/sec.
The graph line joining the two scales meets the central scale,
showing the diameters, corresponding to a value of ~ 90 mm.
Outlet duct
With a flow rate of ~ 400 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 ~ 40 mm.
Optimal speeds that can be obtained with the Booster
pump:
- Suction: ≤ 1 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

As indicated in par. 9.1 in exceptional cases only, the pump
can be controlled by a V-belt system.
For proper layout sizing, consult with our Technical or
Customer Service Departments.
9.11

Transmission of power from the second PTO

Upon request, MF series pumps can be supplied with an
auxiliary PTO on the opposite side to the drive.
Transmission can be carried out:
- By means of V-belts
- By means of a coupling
With V-Belts, Max Torque output is: 150 Nm corresponding to
12.5 kW (17HP) at 800 rpm.
With coupling, Max Torque output is: 220 Nm corresponding
to 18.4 kW (25HP) at 800 rpm.
With transmission by means of a coupling, pay
particular attention to perfect alignment so that
no transverse forces are generated on the pump
shaft.
For applications differing from those specified
above, contact our Technical or Customer Service
Departments.
10

START-UP AND OPERATION

10.1

Preliminary checks

Before start-up, ensure that:
The suction line is connected and pressurised
(see chapter 9): the pump must never run dry.
1. The suction line ensures a hermetic seal over time.
2. Any shut-off valves between the supply source and
the pump are fully open. The outlet line during is free
discharge, to permit rapid expulsion of air present in the
pump manifold and therefore facilitate fast priming.
3. All suction and outlet fittings and connections are
properly tightened.
4. The coupling tolerances on the pump/transmission axis
(half-joint misalignment, Cardan joint tilt, belt pulling,
etc.) remain within limits required by the transmission
manufacturer.
5. Oil in the pump casing is at the required level, verified with
a dipstick (pos. , Fig. 8).
26
1
Fig. 8