Thermostat, coolant - 821704 VALEO

Thermostat is a device for maintaining a static (constant) temperature, as its name implies. There are thermostats of different designs in many devices and mechanisms, from water heaters to refrigerators. There is also a thermostat in a car's internal combustion engine (liquid-cooled, of course). In a car, the thermostat regulates the temperature of the coolant (antifreeze): it accelerates the warm-up of a cold engine and provides heat removal from the hot one. Therefore, the engine works more efficiently and more comfortably for the driver, especially in winter - without a thermostat, the stove would usually blew cold air.

1. MEGANE III Coupe (DZ0/1_)
2. MEGANE CC (EZ0/1_)
3. SANDERO
4. LOGAN (LS_)
5. KANGOO (KC0/1_)
6. CLIO II (BB_, CB_)
7. CLIO Mk II (BB_, CB_)
8. LUTECIA II (BB_, CB_)
9. CLIO MIO II (BB_, CB_)
10. KANGOO Express (FC0/1_)
11. KANGOO Rapid (FC0/1_)
12. LOGAN Pickup (US_)
13. MEGANE Scenic (JA0/1_)
14. MEGANE I Grandtour (KA0/1_)
15. MEGANE I Break (KA0/1_)
16. MEGANE I Coach (DA0/1_)
17. MEGANE I Coupe (DA0/1_)
18. MEGANE I (BA0/1_)
19. MEGANE I Classic (LA0/1_)
20. MEGANE I Cabriolet (EA0/1_)
21. See more in applications

The principle of the thermostat work

The classic VALEO brand Thermostat, coolant is a movable valve that moves due to a change in the external environment - heating or cooling of antifreeze. The thermostat is made of a thermoelement filled with a substance resembling wax in structure - ceresin, with the addition of copper powder, graphite or aluminum for better thermal conductivity. At a certain temperature of the antifreeze, ceresin expands, opening the thermostat valve. When the motor cools down, ceresin contracts and the thermostat closes again.