Thermostat: Description and Operation

DESCRIPTION

Fig.8:

Fig.10:

The engine cooling thermostats are a wax pellet driven, reverse poppet choke type. The thermostat is operated by a wax filled container (pellet), which is sealed. When heated coolant reaches a predetermined temperature, the wax expands enough to overcome the closing spring and water pump pressure, which forces the valve to open. The thermostat is mounted in a housing on the coolant outlet of the engine or.

OPERATION
The engine cooling thermostat is a wax pellet driven, reverse poppet choke type. The thermostat is designed to provide the fastest warm up possible by preventing leakage through it and to guarantee a minimum engine operating temperature of 88 - 93 °C (192 - 199 °F). The thermostat also will automatically reach wide open so it will not restrict flow to the radiator as temperature of the coolant rises in hot weather to around 104 °C (220 °F). Above this temperature the coolant temperature is controlled by the radiator, fan, and ambient temperature, not the thermostat.