Detailed Guide to Valve Stem Seal

The valve stem seal is an important engine seal located between the engine valve and the cylinder head. It is mainly used to prevent the oil from entering the combustion chamber and ensure the lubrication of the valve stem. The following is a detailed introduction to the valve seal, including its structure, material, working principle, advantages and disadvantages, and uses.

1. Structure

The basic structure of the valve seal consists of the following parts:

• Sealing ring: The main sealing component, close to the valve stem to prevent the oil from leaking into the combustion chamber.

• Frame: Usually made of metal, used to support the entire seal structure, maintain its shape and enhance strength.

• Spring: At the top of the seal, there is a small spring ring to ensure that the sealing ring is tightly around the valve stem to maintain good sealing.

• Sealing lip: The part that contacts the valve stem, and the oil flow is controlled by the elasticity of the sealing lip.

2. Material

The material selection of the valve seal is crucial to its sealing performance and life. Common materials include:

• Fluororubber (FKM): It has excellent high temperature resistance and chemical corrosion resistance, suitable for high-performance engines.

• Silicone rubber (VMQ): Excellent high and low temperature resistance, suitable for working in a wide temperature range.

• Nitrile rubber (NBR): Commonly used in ordinary engines, with good oil resistance and wear resistance.

• Polytetrafluoroethylene (PTFE): Used in extreme working environments, with excellent wear resistance and chemical corrosion resistance.

3. Working principle

The main function of the valve oil seal is to control the flow of engine oil to ensure that the valve stem is properly lubricated without allowing too much oil to enter the combustion chamber. The valve oil seal is close to the valve stem. When the engine is running, the valve oil seal controls the leakage of engine oil through the sealing lip to prevent engine oil from entering the combustion chamber and avoid the blue smoke generated by engine oil combustion. At the same time, it maintains the lubrication of the valve stem and reduces friction and wear.

4. Advantages

• Good sealing: The valve oil seal can effectively prevent engine oil from entering the combustion chamber, maintain the good combustion state of the engine, and reduce emissions and oil consumption.

• High temperature resistance: High-quality materials such as fluororubber, silicone rubber, etc. can work stably for a long time in a high temperature environment and adapt to the complex working conditions inside the engine.

• Extend engine life: By controlling the oil flow, the valve seal reduces the wear of the valve stem and valve guide, extending the service life of the engine.

• Maintain engine performance: Avoid carbon deposits after the oil enters the combustion chamber, keep the combustion chamber clean, and improve the combustion efficiency of the engine.

5. Common problems and impacts

• Excessive oil consumption: Failure of the valve seal will cause too much oil to enter the combustion chamber, increase oil consumption, and may produce blue smoke.

• Reduced engine performance: Oil leakage into the combustion chamber will cause carbon deposits to form, affecting the normal combustion of the engine and reducing performance.

• Environmental pollution: Failure of the valve seal causes oil combustion, which not only increases emissions, but may also pollute the environment.

Summary

The valve seal plays a vital role in the engine sealing system. By controlling the lubrication of the valve stem and preventing oil from entering the combustion chamber, it can not only extend the life of the engine, but also improve combustion efficiency and reduce emissions. High-quality materials and correct installation are essential for the long-term performance of the valve seal. Jinwoseal provides you with a variety of high-quality materials and different sizes to choose from, come and order.