Valve Stem Seal

Due to emissions laws, coupled with the fact that today's engines run hotter and valves open and close up to 100,000 times an hour, your stem seals have to be of good quality. NNK valve stem seals are made of the highest quality materials and the latest technology, ensuring tightness while extending service life and reducing replacement frequency.

The function of the valve stem seal

Valve stem seals are installed in the valve guides and slide to control valve stem lubrication. Too little oil can cause stem and guide wear. Too much oil can increase oil consumption and cause carbon deposits, which can lead to valve seat damage and premature valve wear. At the same time, if the valve stem seal is damaged, it will also increase the fuel consumption.

NNK valve stem seal design:

Positive seals : Attach to the valve guide boss. They work like a squeegee, wiping and metering oil on the stem as it passes through the seal.

Deflector seals: Deflect oil away from the valve stem. Also called umbrella seals, they move with the valve stem to shield the valve guide from excess oil.

Stem Seal Materials: Nylon, Teflon, Steel, and Synthetic Rubber (NBR, Polyacrylate, and Viton).

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DAIHATSU，ISUZU，MAZDA，MITSUBISHI，NISSAN，TOYOTA ，SUZUKI，KOMATSU，DAEWOO，HYUNDAL，BMW

NNK and valve stem seals：

In order to prevent premature hardening and rupture due to insufficient heat resistance of rubber seals, NNK guarantees the service life and ensures that the engine is in a lubricated state. The materials we choose are based on the use environment of the seals and the characteristics of the materials themselves. The oil seals produced have high-quality properties such as high temperature resistance, wear resistance, and long service life. Currently, Viton has excellent heat resistance (up to 450° F) and abrasion resistance and is the material of choice for most valve stem seals. If you have any valve stem seal needs, please contact us.