Marine Installation Manual
2021-08
4-12
4 Ancillary Systems
4.2 Cooling water system
X72DF
Buffer unit supply pump
The buffer unit supply pump compensates for losses in the CCW system. This
pump is automatically controlled by the water level in the buffer unit.
It is also advisable to monitor the running period of the supply pump. Moni
-
toring of the pump running period will warn when the running period exceeds a
pre-set value, indicating unusual water losses in the system. Spare parts for the
supply pump must be available according to classification societies' require
-
ments.
Automatic
temperature control valve
Pump type
Centrifugal or positive displacement
Capacity
0.5m
3
/h
Delivery head
4bar (can be adjusted depending on project-specific design)
Valve type
Electrically or electro-pneumatically actuated three-way type
(butterfly valves are not adequate) having a linear characteristic
Design pressure
5bar
Test pressure
Refer to specification laid down by classification society
Press. drop across valve Max. 0.5bar
Controller
Proportional plus integral (PI), known as proportional plus reset
for steady state error of max.
±
2°C and transient condition
error of max.
±
4°C
Temperature sensor
According to control valve manufacturer's specification; fitted in
engine outlet pipe