Product Material

Valve stem seals are critical components in internal combustion engines, preventing oil from leaking into the combustion chamber while maintaining dynamic sealing during high-speed valve motion under elevated temperatures.

We provide a range of high-performance rubber materials for valve stem seals, including:

NBR (Nitrile Rubber): Cost-effective with good oil resistance, suitable for standard operating temperatures.

ACM (Acrylic Rubber): Offers superior heat and oil resistance, widely used in high-temperature Japanese engines.

HNBR (Hydrogenated Nitrile Rubber): Excellent durability and mechanical strength under high temperature and pressure conditions; ideal for performance engines.

FKM (Fluoroelastomer / Viton®): Outstanding thermal and chemical resistance with low permeability to combustion gases; used in turbocharged, diesel, or high-performance engines.

Custom formulations for specific operating conditions (e.g., oil type, peak temperature, engine design) are also available to ensure optimized sealing and long-term durability.

Our Advantages

1. The Standard Product Inventory is Wide and Complete: NIYOK stocks the standard products and supplies the most common inch sizes. It can manufacture precise Valve Stem Seal according to various industrial needs and deliver them quickly and on time, made of high-quality rubber, with good performance.
2. Low Mold Cost: Most of the various Valve Stem Seal standard specifications already have molds, and no additional investment is required. If there is a special size that needs to be opened, we will also give back to the customer at low cost, or jointly develop the model for cooperation.
3. Flexible MOQ and Instant Delivery: It can support small orders from customers, MOQ is smaller than the industry, and sample testing is provided. Instant delivery allows customers to apply production scheduling more flexibly.
4. Auto Assembly Machine for Oil Seal Spring was introduced, the oil seal is more precise and faster production when inserting the spring, so that the delivery time and quality are more stable.
5. Fully Automatic Inspection: In 2020, the automatic inspection was introduced to ensure the quality of oil seal, overcome the bottleneck of manual inspection, and produce more efficient and fast output.
6. Provide Customized Services: In case there is a need for customized Valve Stem Seal, you are welcome to leave relevant information such as CAD / CAM, NIYOK can do advanced planning services and consulting for you.

Valve Stem Seal can prevent leakage and pressure in the engine and maintain normal pressure. It also can prevent engine oil from entering the combustion chamber and avoid engine oil loss. The valve stem seal is one of the important parts of the entire engine. It is usually in contact with gasoline and engine oil at high temperatures, therefore, heat-resistant, and oil-resistant rubber materials are required, so Fluorine rubber is a common choice.