Doosan P158LE -III, Руководство по эксплуатации и техническому обслуживанию

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Maintenance of Major Components - 127 -
5.2.2. Thermostat
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General descriptions and main data
The thermostat maintains a constant
temperature of coolant (71 ~ 85 °C) and
improves thermal efficiency of the engine
by preventing heat loss.
Namely, when the temperature of
coolant is low, the thermostat valve is
closed to make the coolant bypass to
directly enter the water pump; when the
coolant temperature rises to open wide
the thermostat valve, the bypass circuit
is closed and the water passage to the
radiator is opened so that the coolant is
forced to flow into the radiator.
NOTE :
There are 2 kinds of thermostats according to surrounding and operating conditions.
One is named by 71 °C type and the other is 79 °C.
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Inspecting
(1) Check the wax pallet and spring for
damage.
(2) Put the thermostat in a container of
water, then heat the water slowly
and check temperature with a
thermometer. If the valve lift is
0.1 mm (starting to open) at
temperature of 71 °C and 8 mm or
more (opening wide) at temperature
of 85 °C, the thermostat is normal.
Item
Specifications
In moderate climates
In tropical climates
Generator
Type Wax-pallet type Wax-pallet type
Open at 71 °C 79 °C
Open wide at 85 °C 93 °C
Valve lift 8 mm or more 8 mm or more
EC8OM005
To radiator
Bypass
valve
From cooling
water pump
To bypass
tube
EFM2055I
Thermometer
Wood plate
Bar