Yanmar 4LHA-HTP, Operation Manual

Page: 528 / 670

Chapter 6 Cooling Water System
4. Heat Exchanger
, 4LHA Seri
4-2 Specifications of heat exchanger
Radiation area m
2
(in.
2
) 0.593 (919)
Fresh water discharged volume £/hr(in.
3
/hr)
8.000 (488.160)
Sea water discharged volume
^/hr(in.
3
/hr)
6.000 (366.119)
Fresh water flow speed in cooling pipe m/s (ft/s) 1.5 (4.9)
Sea water flow speed in cooling tube
m/s (ft/s) 2.17 (7.12)
4-3 Disassembly and reassembly of the heat
exchanger
(1) Remove the covers on both sides and take out the cool-
ing pipe and O-ring(s).
NOTE: Replace the O-ring(s) when you have removed the
cooling pipe.
(2) Remove the filler assembly.
4-4 Heat exchanger inspection
(1) Cooling pipe inspection
1) Inspect the inside of the tubes for rust or scale build-
up from sea water, and clean with a wire brush if
necessary.
NOTE: Disassemble and wash when the cooling water
temperature reaches 85
0
C.
2) Check the joints at both ends of the tubes for
looseness or damage, and repair if loose. Replace if
damaged or corroded.
3) Check tubes and replace if leaking.
4) Clean any scale or rust off the outside of the tubes.
(2) Heat exchanger body inspection
1) Check heat exchanger body and side cover for dirt and
corrosion. Replace if excessively corroded, or cracked.
2) Inspect sea water and fresh water inlets and outlets,
retighten any joints as necessary and clean the insides
of the pipes.
3) Check the exchaust gas intake flange and line, and
replace if corroded or cracked.
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