Valve stem seal is a type of oil seal, generally made of vulcanised exoskeleton and fluoroelastomer, with a self-tensioning spring or steel wire installed at the diameter of the seal, used to seal the engine valve guide rod.The valve stem oil seal are located in the cylinder head,under the valve springs,installed around and sealing the valves.They are located under the valve springs,so you might have to remove the valve cover to see them. 
The valve oil seal prevents the oil from entering the intake and exhaust pipes, prevents the loss of oil, prevents the gasoline and air mixture and the exhaust gas from leaking, and prevents the engine oil from entering the combustion chamber. The valve oil seal is one of the most important parts of the engine valve train and is in contact with petrol and oil at high temperatures, so it needs to be made of a material with excellent heat and oil resistance, usually made of Viton.
Valve oil seals have two main functions.
1、To prevent leakage of gasoline and air mixtures as well as emission exhaust gases.
2、Prevents engine oil from entering the combustion chamber.
Valve oil seal material.
NBR, Viton, Silicone, Acrylic, Polyurethane, PTFE, etc. When selecting the material for the oil seal, consideration must be given to the material’s
Compatibility of the material with the working medium, adaptability to the working temperature range and the ability of the lip to follow the rotation of the shaft at high speed. In general, the temperature of the lip of the oil seal
Therefore, when choosing oil seals, we should pay great attention to the selection of oil seal materials.
Xingtai Xinchi is a leading supplier and seller of oil seals, selling high-quality industrial and engineered parts made from a variety of materials. Browse our online store to see our full range of products, and contact us to get the quote.
Post time: Jan-03-2023