Automotive parts related business

Radiator cap

Radiator cap

Radiator cap is an important part for cars.

At first glance, it is a small part, but it plays an important role.
Although it looks like a lid, it is not just a lid. Three valves on the back of the cap play three roles: they keep the pressure of the radiator normal and prevent the coolant from boiling and vaporizing when the water temperature rises.

cap description
Pressurized valve
As the temperature of the cooling water rises, the pressure in the radiator goes up and the boiling point of the coolant also rises. If the boiling point increases, it exerts a cooling effect even at 100 degrees or more. Therefore, if it exceeds the pressure set there, the pressurizing valve will be opened to release extra cooling water into the reservoir tank.
Negative pressure valve
The pressure in the radiator also drops by releasing the cooling water to the reservoir tank. When the pressure in the radiator is negative, the radiator fails, so when the radiator is broken, the negative pressure valve is opened, and the pressure is adjusted by returning the cooling water from the reservoir tank.
Closed valve
A closed valve that seals so that cooling water does not leak from the radiator.
Periodic inspection and replacement

Radiator cap is an important part that keeps the pressure of the cooling cycle properly.
Due to the dirt, rusting, deposits, seal deterioration, deformation, damage, etc. of the radiator cap, the operation is worse and it may cause radiator leakage and overheat.
In order to keep the inside of the radiator normal, the rubber packing of the cap should be visually checked for deterioration or deformation, and if it is difficult to understand, it should be inspected or replaced using a tester to keep proper pressure.

check image


Radiator cap specification and design can be changed in accordance with various uses.
If you are interested in OEM, please feel free to contact us.

Model Spec Type
S905 49kPa | 0.5kgf/㎠ Type-B
S109 88kPa | 0.9kgf/㎠ Type-C
S209 88kPa | 0.9kgf/㎠ Type-D
S909 88kPa | 0.9kgf/㎠ Type-B
S211 108kPa | 1.1kgf/㎠ Type-D
S311 108kPa | 1.1kgf/㎠ Type-C
Model Spec Type
DB05 49kPa | 0.5kgf/㎠ Type-B
DC09 88kPa | 0.9kgf/㎠ Type-C
DD09 88kPa | 0.9kgf/㎠ Type-D
DB09 88kPa | 0.9kgf/㎠ Type-B
DD11 108kPa | 1.1kgf/㎠ Type-D
DC11 108kPa | 1.1kgf/㎠ Type-C


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