Flushing-Liquid Connections; Startup - Grundfos CR 95-155 Manual Del Usuario

6. Flushing-liquid connections

Legend to the letters used in the drawings:
Pos. A = pumped liquid.
Pos. C/D = outlet, flushing liquid.
Pos. E = inlet, flushing liquid, CR, CRN. Figure 4, show seal
chamber connections for flushing liquid. They also show where to
fit the sensor (pos. A), if retrofitted.
Minimum 1 metre
C/D
Outlet 1/2"
Fig. 1 Tandem seal arrangement with circulating flushing
liquid
In fig. 1, the flushing liquid circulates between an elevated tank
and the pump by natural circulation. Heated flushing liquid rises
from the seal chamber to the tank where it cools down. The
cooled-down flushing liquid returns to the seal chamber.
At high temperatures, the circulation of flushing liquid through the
seal chamber cools the seal faces of the shaft seal and reduces
noise.
Fig. 2 Tandem seal arrangement with flushing-liquid supply
In fig. 2, the flushing liquid enters the seal chamber via a pipe
from an elevated tank. The flushing liquid in the seal chamber
prevents leakage of pumped liquid to the environment.
No heat is dissipated from the system.
6
E
Inlet 1/2"
E
Inlet 1/2"
C/D
Outlet 1/2"
Fig. 3 Tandem seal arrangement with flushing liquid
connected to a drain
In fig. 3, the flushing liquid enters the seal chamber via a pipe
from a central flushing system.
In case of seal leakage, the pumped liquid is washed away to the
drain by the flushing liquid.
C/D
Inlet 1/2"
E
A
Fig. 4 Seal chamber CR, CRN 95, 125, 155

7. Startup

See also installation and operating instructions for the standard
pump.
Before startup, the seal chamber and the pump must
Caution
be completely filled with liquid and vented.
1. Start the pump, and check the direction of rotation.
See the correct direction of rotation on the motor fan cover.
The seal chamber must always be filled with the
Caution
flushing liquid during operation. Risk of dry-running.
E
Inlet 1/2"
C/D
Outlet 1/2"
E
Sensor
A