Yaroslavl Engine Plant YMZ-536, Operation Manual

Page: 87 / 168

87
Installed in the oil filter housing is the L/O HE safety valve
(Fig. 27). When the differential pressure before and after the heat-
exchanger reaches 274 ± 40 kPa (2,8 ± 0,40 kgf/cm
2
), the valve opens
and part of the oil is supplied uncooled directly to the oil filter. The
valve design is shown in Fig. 27a.
Fig. 27 а . L/O HE safety valve:
1
– plunger;
2
– spring;
3
– adjustment shim;
4
- plug
THERMOSTATS
The cooling liquid temperature is controlled by two thermostats
located in the service module housing (see Fig. 28). The valve starts
opening at 83

С . The valve lift 9.4 mm (fully open) is reached when
the cooling liquid temperature is 98

С .
ATTENTION! AS THE THERMOSTATS ARE ARRANGED IN THE
SERVICE MODULE HORIZONTALLY, THEY MUST BE
INSTALLED WITH THE STEAM EXHAUST VALVES LOOKING
DOWN.