Outlet Line; Calculation Of The Internal Diameter Of The Duct Pipes; Start-Up And Operation; Preliminary Checks - Pratissoli LK Serie Manual De Uso Y Mantenimiento

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.
9.7

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, see graph in par. 9.8.
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. The outlet line must always be equipped with a safety
valve.
5. Use pressure gauges capable of withstanding the
pulsating loads typical of plunger pumps.
6. 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.
7. For applications in which pulses produced by the pump
on the outlet line may prove harmful or are anyway
undesirable, install a pulsation dampener of sufficient size.
9.8 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.
10

START-UP AND OPERATION

10.1

Preliminary checks

Before start-up, ensure that:
The suction line is connected and pressurized
(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 is free discharge, to
permit rapid expulsion of the 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
shaft (half-joint misalignment, Cardan joint angle, etc.)
remain within the limits required by the transmission
manufacturer.
5. Oil in the pump casing is at the required level, verified
with the level indicators at the sides of the casing (pos. ,
Fig. 8).
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