English (GB)
15
6.7 Bypass pipe
6.7.1 Air-cooled engine
Install a bypass pipe from the suction side of the pump to the test
pipe to guarantee that the pump is not running against a closed
valve. See section
. The suction pipe must
have a port for the bypass pipe.
6.8 Connecting the cooling system
Water-cooled diesel engines are cooled by a flow of water
through a pipe connected to the heat exchanger via a cooling
circuit.
The cooling circuit consists of the pipework with both a main pipe
and a bypass pipe, isolating valves, pressure reduction valves,
filters, a pressure gauge as well as a solenoid valve depending
on the configuration. See figs 16 and 17.
Fig. 16
Cooling pipe with solenoid valve
Fig. 17
Cooling pipe without solenoid valve
Install a pipe on the discharge side of the heat exchanger.
See fig. 18. The nominal diameter of the pipe must not be smaller
than the outlet of the heat exchanger (1 1/4" or 1 1/2").
Fig. 18
Outlet of the heat exchanger
If it is an installation with cooling water that is returned to the storage
tank, use a cooling pipe without solenoid valve. See fig. 17.
If it is an installation with cooling water that is led to the drain, use a
cooling pipe with solenoid valve. See fig. 16.
6.8.1 Minimum pressure
To ensure correct cooling of the motor, there must be the below-
mentioned pressure after the dirt trap.
6.8.2 Filter in cooling circuit
The isolating valves in the bypass pipework are closed during
normal operation. Only open the valves if the filter in the main
pipe is fouled and thus keeps the cooling water from cooling the
motor. A fouled filter will result in lack of pressure on the pressure
gauge.
Note
This section applies to pump sets with water-
cooled diesel engine.
T
M
05
97
12
44
13
T
M
05
97
12
44
12
3
TM
04 98
48 021
1
Warning
If the cooling water is not connected correctly, it
might lead to draining of the storage tank.
Type
Pressure
[bar]
Cooling water returned to storage tank
2.0
Cooling water led to drain
1.0
Summary of Contents for Fire NKF Series
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