Why are some cars having coolant pots sealed while others are not?

Automobile antifreeze is also called coolant, it is not difficult to see from the name that it has the function of antifreeze and cooling, freezing point and boiling point are also two important criteria for evaluating the quality of antifreeze. The characteristic of antifreeze is that the freezing point is low, which prevents the tank from becoming larger due to freezing; The boiling point is higher, so that it does not boil at higher temperatures, preventing the engine from "boiling".

In general, although the car antifreeze will also be naturally lost, the amount of loss is very small, because the engine cooling system itself is a sealed environment. From the coolant kettle, to the cooling tank, to the pump, there are either pipes or the engine itself, and nothing is exposed to the external environment. Even if it is vaporized at high temperatures, it will still return to the cooling system after condensation.

First of all, let's talk about the reason for the natural loss of coolant, the above also said that although the coolant has a high boiling point, it will also vaporize under the influence of high temperature, from liquid to gas, we all know that the volume will increase, but the cooling system as a sealing system, the pressure is small and can withstand it, if the coolant vaporizes more and more, the pressure is getting bigger and bigger. This part of the pressure must be "unloaded", how to unload? At this time, the coolant (expansion) kettle lid comes into play, and the kettle lid has an automatic pressure relief function, and the gas discharged at this time is the gas after the coolant is vaporized, which is also the main reason for the natural consumption of coolant.

The reason why the coolant kettle is forbidden to be unscrewed when the vehicle is high temperature is to prevent the pressure from suddenly decreasing, and the high-temperature coolant spraying out and burning people. Attentive car owners will also find that the moment the coolant kettle lid is unscrewed, the coolant level will rise a little bit, which is also due to the removal of pressure.

The coolant, to the cooling tank, to the pump, is either the pipe or the engine itself, all sealed.

The point is lower, so that it can prevent the situation where the volume becomes larger due to icing, which leads to the expansion of the tank; The boiling point is higher so that it does not boil at higher temperatures.

The characteristic of antifreeze is that the freezing point is low, which prevents the tank from becoming larger due to freezing;

However, the cooling system is a sealed system, and the pressure is small, and it can withstand it, such as coolant.

What if there is more and more vaporization, and the pressure is increasing?

Items can't be static, and a variety of goods can have a better shipment rate.

Because the engine cooling system itself is a sealed environment.

Although automotive antifreeze is also naturally lost, the amount of loss is very small because the engine cooling system itself is a sealed environment.

Because some night pots are made of different materials, the sealing situation is also different.

What is not sealed is because it has been used, so it has been disassembled, but it does not affect the continued use.

This has something to do with the structure of the car, with some engines in front and some in the rear.