Min Back Pressure; Min Flow Required; Temperature Range; Max Temperature Versus System Pressure - Johnson Pump MDR Series Instruction Manual

2.3 Min back pressure

The MDR-series demands a
certain head for good function.
Min head = 0.5 m wc or 0.05 bar
manometric pressure. If less,
install a valve in the discharge
pipe to adjust head.

2.4 Min flow required

To cool and lubricate the impeller bearing and shaft a certain flow
is required through the pump.
Min. flow
l/min
MDR45
MDR75
MDR85
MDR105 10
MDR116 10

2.5 Temperature range

P2 (PVDF) = -10°C - +100°C
P3 (PP) = -10°C - + 85°C

2.6 Max temperature versus system pressure

p (bar)
4
3
2
1
10 20
Valid for P3 (polypropylene) pumps tested in water
10
Max. system pressure
bar (20°C)
3 3
5 3
7 3
3
3
MDR45 / 85 / 105 / 116
30 40 50
H
Pump
MDR75
60 70 80
MDR/EN (0909) 1.0
90
°C