The first function of the water tank cover is of course to close the water tank tightly, but please remember that the water tank looks like it has only one opening, but it has two inner diameters, so there are actually two openings, corresponding to the two rings of rubber strips on the water tank cover. The large outer circle is to ensure that the water in the water tank will not leak out of the entire cooling system, while the small circle of rubber strips is to ensure that when the internal pressure of the water tank is not too high, that is, when the water temperature is not too high, the cooling water will not overflow to a small amount. In the water tank. Therefore, you can also see that there is a small spring in the water tank cover. This spring is the key to controlling when the water from the big water tank overflows to the small water tank.

As we all know, when the water temperature rises, the volume of the water will expand. When it expands to a certain level, the water pressure will push the spring open, thereby opening the ring of small rubber strips, causing the water in the large water tank to overflow into the small water tank. Therefore, the pressure of the large water tank is reduced, and the cooling pipe and the water tank will not explode. When the water temperature of the large water tank is reduced, the pressure is reduced to a certain extent. At this time, a certain vacuum is formed due to the reduction of the volume of water in the large water tank. At this time, the vacuum valve on the water tank cover will work, which will make the water in the small water tank flow back to the large water tank, causing the water in the cooling system to be full to ensure heat dissipation efficiency.

The pressure that the spring in the stainless steel water tank cover can withstand becomes the key to the pressure and temperature of the cooling system. Generally, the pressure of the water tank cover of a car is 0.9-1.1Mpa. If the pressure is greater than this pressure, the spring will move. Within this pressure range, the pressure in the water tank Water can reach a high temperature of 105 degrees, but it does not boil. The water tank factory reminds users that the stainless steel water tank cover must be tightly closed, and that the spring in the water tank cover must not be rusted. Once it is rusted, it cannot move, which will cause excessive pressure in the cooling system.