Special Versions; Mkr-Mksr Pump - Pratissoli MK-MKS Serie Manual De Uso Y Mantenimiento

17

SPECIAL VERSIONS

The MK pump is also available in the following special
versions:
• MKR (for Recirculated Water)
• MKSR (for Recirculated Water)
• MKC (for Methanol)
• MKSC (for Methanol)
The following information is helpful in deciding how to
choose and use these versions.
Unless specified otherwise, observe the above instructions for
the standard MK pump.
17.1.3 Technical characteristics
Model
MKR 50
MKR 55
MKR 60
MKR 65
Model
MKSR 50
MKSR 55
MKSR 60
MKSR 65
17.1.4 Dimensions and weight
For the dimensions and weight of the pumps, refer to the
diagrams in chapter 6.
17.1.5 Pump supply
The pumps must always be installed with a suction head, that
is they must receive the water by gravity or by forced feeding,
but never draw it from a lower level.
The pumps are able to withstand minimum suction heads of
even 1 metre, however, for the best
volumetric efficiency and above all to avoid cavitation, the
available positive suction head
(NPSH avail) measured at the suction flange in the head must
be equal to or greater than the values below.
NPSH
MKR/MKSR50
6.5
MKR/MKSR55 7.5
MKR/MKSR60
8
MKR/MKSR65 9
Flow rate
Rpm
l/min
1500 240
1800 232
1500 290
1800 281
1500 346
1800 334
1500 406
1800 392
Flow rate
Rpm
l/min
1500 287
1800 288
2200 284
1500 347
1800 348
2200 343
1500 413
1800 415
2200 408
1500 485
1800 487
2200 479
(m)
r
46
17.1

MKR-MKSR pump

17.1.1 Operating instructions
The MKR/MKSR series pumps have been designed to
operate in environments with atmospheres that are
not potentially explosive and for using water rich in
particulate, therefore they are considered ideal for
systems with fluid recirculation.
The durability of the piston seals is directly in
relation to the percentage of the presence of solids
in the fluid as regards both their size and their
density.
For a long seal life we recommend a particulate
grain size of no more than 200 micron and 20% max.
in volume.
For more information and a general system layout,
see par. 17.2.6.
17.1.2 Maximum pressure and flow rate
The rated specifications stated in our catalogue are the
maximum that can be obtained by the pump. Independently
of the power used, the maximum pressure and rpm indicated
in the specification label can never be exceeded unless upon
prior formal authorisation by our Technical or Customer
Service Departments.
Pressure
Gpm bar psi
63.4 250 3625
61.3 250 3625
76.6 200 2900
74.2 200 2900
91.4 170 2465
88.2 170 2465
107.3 150 2175
103.6 150 2175
Pressure
Gpm bar psi
75.8 250 3625
76.1 250 3625
75 250 3625
91.7 200 2900
92 200 2900
90.6 200 2900
109.1 170 2465
109.7 170 2465
107.8 170 2465
128.2 150 2175
128.7 150 2175
126.6 150 2175
For the greater displacements, of the pumps with piston
Ø 55 - 60 - 65, forced feeding by a booster pump is highly
recommended in order to avoid cavitation, considering the
geometry of the hydraulics and the considerable flow rates.
The booster pump must have at least twice the flow rate of
the rated flow rate of the plunger pump and a pressure of
between 2 and 3 bar.
These supply conditions must be observed at all operating
speeds.
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.
Power
kW HP
115 156
111 151
111 151
107 146
112.5 153
108 147
116 158
112.5 153
Power
kW HP
137 186
137.5 187
135.5 184
132.5 180
133 181
131 178
134 182
134.5 183
132.5 180
139 189
140 190
137.5 187