Hydraulic Connections; Pump Supply; Suction Line; Outlet Line - Pratissoli MK9M Serie Manual De Uso

9.4

Hydraulic connections

In order to isolate the system from vibrations produced by
the pump, it is advisable to make the first section of the duct
adjacent to the pump (both suction and outlet) with flexible
piping. The consistency of the suction section must be such as
to prevent deformations caused by vacuums produced by the
pump.
9.5

Pump supply

A positive head of at least 0.20 meters is recommended for
the best volumetric efficiency, to be increased with increasing
fluid density.
For the priming conditions see the chart in
par. 9.8.
9.6

Suction line

For a smooth operation of the pump, the suction line should
have the following characteristics:
1. Minimum internal diameter for pipes of length less than 8
m. Ø 90 mm.
The pipe must be rigid enough to avoid self-constriction
caused by the pressure drop.
Localized 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.
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
partial.
5. Do not use 3 or 4-way hydraulic fittings, adapters, swivel
joints, etc. as they could jeopardies pump performance
due to excessive head losses.
6. Avoid use of base valves or other types of unidirectional
valves.
7. Do not recirculate by-pass valve discharge directly into
suction.
8. Provide for proper guards inside the tank to prevent that
bentonite flow from the bypass and the tank supply line
can create vortexes or turbulence near the pump supply
pipe port.
9. Make sure the suction line is thoroughly clean inside
before connecting it to the pump.
9.7

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.
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. Use pressure gauges suitable to withstand pulsating loads
typical of the plunger pumps.
5. 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.
6. 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.
9.8

Typical Diagram

For MK9M5B and MK9M8B pumps refer to Fig. 7.
For MK9M5D and MK9M8D pumps refer to Fig. 7/a.
9.9

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.
25
Fig. 7
Fig. 7/a