Maximum Permissible Operating Pressure And Liquid Temperature For The Shaft Seal; Minimum Flow Rate; Installation; Pump Location - Grundfos CRK Series Installation And Operating Instructions Manual

6.4 Maximum permissible operating pressure and
liquid temperature for the shaft seal
p
[psi]
400
300
200
HUUV
100
0
0 20 40 60 80 100 120 140 160 180 200 220
Fig. 3 MTR 1s to 64
p
[bar]
35
30
25
20
15
HUUE / HUUV
10
5
0
-20 -10 0 10 20 30 40 50 60 70 80 90 100 110
Fig. 4 MTR 1s to 64 [metric]
p
[psi]
400
300
200
AUUV
100
0
0 20 40 60 80 100 120 140 160 180 200 220
Fig. 5 CRK and SPK
p
[bar]
30
25
20
AUUV
15
10
5
0
-40 -20 0 20 40 60
Fig. 6 CRK and SPK [metric]

6.5 Minimum flow rate

Due to the risk of overheating, the pump should not be used at
flows below the minimum flow rate.
The curve below shows the minimum flow rate as a percentage of
the nominal flow rate in relation to the liquid temperature.
Qmin
[%]
30
20
10
0
104 140 176
40 60 80
Fig. 7 Minimum flow rates
T [°F]
T [°C]
T [°F]
80 100 120 140 160
T [°C]
212 248 284
T [°F]
Qmin
[%]
15
10
5
0
40 50 60 70
Fig. 8 Minimum flow rates [metric]
Note: The pump must never operate against a closed discharge
valve.

7. Installation

The pump must be installed so that persons
cannot accidentally come into contact with the
hot surface of the motor.

7.1 Pump location

The pump is designed for tank mounting in vertical position. The
pump is positioned in a hole cut into the cover of the tank (upper
side) and is secured to the tank by four hexagon head screws
through the holes in the mounting flange. It is recommended to fit
a sealing gasket between the pump flange and tank.
If the pump is to be installed horizontally (MTRI[E] 1s to 20, CRK2
and 4, and SPK only), the drain hole of the motor stool must be
fitted with a plug and four closed nuts with O-rings must be fitted
to the straps.
Tank must be drained to change shaft seal in the
Caution
event of leakage in horizontally mounted pumps.
Closed nut
Fig. 9 Horizontal installation (MTRI[E] only)
Note: MTR 32, 45 and 64 pumps can only be installed in vertical
position.
80 90 100 110
T [°C]
Drain plug
5