Pump Supply; Suction Line; Filtration - Pratissoli KS Série Manuel D'utilisation Et D'entretien

9.5

Pump supply

KS pumps require a minimum positive suction head (NPSHr),
measured on the head suction flange, indicated in the
following table (obtainable with the booster pump):
KS 28 KS 32
NPSH (m)
2.0 2.5
r
The booster supply pump must have the following features:
Flow rate at least twice the rated flow rate of the plunger
pump with a sufficient minimum pressure for the required
NPSHr and max 6 bar.
These supply conditions must be observed at all operating
speeds.
The operation of the booster pump must be independent
from that of the plunger pump.
The booster pump must always be started up
before the plunger pump.
It is advisable to install a pressure switch on the
supply line downstream of the filters protecting
the pump.
For any supply conditions other than those specified
above, contact our Technical or Customer Service
Departments.
9.6

Suction line

For a smooth operation of the pump, the suction line should
have the following characteristics:
1. Minimum internal diameter as indicated in the graph in
par. 9.9 and in any case equal to or exceeding that of the
pump head.
Localised restrictions should be avoided
along the run of the duct, as these can cause
load losses resulting in cavitation. Avoid 90°
elbow bends, connections with other piping,
constrictions, counterslopes, inverted U- curves and
T-connections.
9.7

Filtration

Two filters must be installed on the pump suction line, positioned as indicated in Fig. 7 and Fig. 7/a.
With a manually activated control valve
Inlet
Supply tank
2. With a layout that is set in such a way to prevent
cavitation.
3. Completely airtight and constructed to ensure sealing
over time.
4. Prevent that pump stopping causes emptying, even
KS 36 KS 40
partial.
3.0 4.0 5. Do not use 3 or 4-way hydraulic fittings, adapters, swivel
joints, etc. as they could jeopardise pump performance.
6. Do not install Venturi tubes or injectors for detergent
suction.
7. Avoid use of base valves or other types of unidirectional
valves.
8. Do not recirculate by-pass valve discharge directly into
suction.
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.
Bypass
29
1 Filter 1 7 Pressure gauge
2 Booster Pump 8 Safety valve
3 Filter 2 9 Accumulator
4 Pressure gauge 10 Control valve
5 Pressure switch
6 Plunger pump
Fig. 7