Thermostat, coolant - 819716 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. X-TRAIL (T31)
2. X-TRAIL SUV (T31)
3. LATITUDE (L70_)
4. QASHQAI / QASHQAI +2 I (J10, NJ10, JJ10E)
5. DUALIS I (J10, NJ10, JJ10E)
6. LAGUNA II (BG0/1_)
7. LAGUNA II Grandtour (KG0/1_)
8. LAGUNA II Sport Tourer (KG0/1_)
9. ESPACE IV (JK0/1_)
10. ESPACE Mk IV (JK0/1_)
11. MEGANE II (BM0/1_, CM0/1_)
12. MEGANE II Estate (KM0/1_)
13. MEGANE II Grandtour (KM0/1_)
14. MEGANE II Sport Tourer (KM0/1_)
15. MEGANE II Coupe-Cabriolet (EM0/1_)
16. SCENIC II (JM0/1_)
17. VEL SATIS (BJ0_)
18. MEGANE II Saloon (LM0/1_)
19. LAGUNA III (BT0/1)
20. LAGUNA III Grandtour (KT0/1)
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.