THERMOSTAT COOLANT FOR RENAULT 18/Variable/Break/Van/Société 20 21/Savanna 25 VALEO 819937

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. SIERRA (GBG, GB4)
2. SIERRA Hatchback (GBC, GBG)
3. GRANADA (GU)
4. SCORPIO I (GAE, GGE)
5. GRANADA Mk III� (GAE, GGE)
6. GRANADA I (GAE, GGE)
7. SCORPIO I Saloon (GGE)
8. GRANADA Mk III� Saloon (GGE)
9. GRANADA Mk III Saloon (GGE)
10. TRANSIT Bus (V_ _)
11. TRANSIT Bus (T_ _)
12. SIERRA Hatchback (GBC)
13. SIERRA Turnier (BNC)
14. SIERRA Break (BNC)
15. SIERRA Turnier (BNG)
16. GRANADA Turnier (GNU)
17. GRANADA Break (GNU)
18. SCORPIO I Turnier (GGE)
19. SCORPIO I Break (GGE)
20. GRANADA Mk III� Turnier (GGE)
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.