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

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 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 air present in the pump head to come
out quickly and therefore favour 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, etc.) remain
within 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).
In case of prolonged storage or long-term inac-
tivity, you need to restore the proper functioning
of the suction valves by opening the three valve-
lift devices (see pos.  Fig. 9). Make sure you
have closed the valves before starting the pump.
For the "work" and "rest" positions, see Fig. 10.
VALVE CLOSED - SAFETY DEVICE
WORK POSITION -
32
Fig. 8
Fig. 9
VALVE OPEN - REST
RELEASE POSITION -
Fig. 10