Hangzhou Bright Rubber Plastic Product Co., Ltd. is one of the leading manufacturers and suppliers of green polyurethane un u-cup seal for hydraulic cylinders in China. If you're going to buy green polyurethane un u-cup seal for hydraulic cylinders made in China, welcome to get more information from our factory. We also accept customized orders.
Material & Wear Resistance
Manufactured from high-grade Polyurethane (PU), this hydraulic seal significantly outperforms standard rubber seals in harsh, abrasive environments. The material exhibits exceptional tear resistance and mechanical strength, preventing damage from metal-to-metal contact and contaminated hydraulic fluids. Unlike NBR rubber, which may degrade quickly under heavy loads, PU maintains its structural integrity and elasticity over millions of cycles. This makes it highly reliable for heavy machinery, construction equipment, and industrial hydraulic systems where durability and longevity are critical for reducing maintenance downtime and overall operational costs.
U-Cup Design & Sealing Principle
Featuring a classic U-cup cross-section, this seal utilizes system pressure to energize the sealing lips. As hydraulic pressure increases, the lips are pushed tighter against the cylinder wall and rod, creating a self-energizing, highly effective dynamic seal. This design compensates for minor wear on the sealing surface and ensures a leak-free barrier during continuous reciprocating movement. Unlike standard TC rotary oil seals that rely purely on a spring, this pressure-activated design guarantees optimal sealing performance even under fluctuating pressure conditions and severe mechanical vibrations.
High Pressure & Extrusion Resistance
Designed specifically for high-pressure hydraulic applications, this PU U-cup seal can withstand working pressures up to 30-40 MPa, depending on the hardness grade selected. Its high hardness and structural integrity effectively prevent the seal from being extruded into the clearance gap between the piston and cylinder bore. This anti-extrusion property is essential for maintaining system stability and safety, especially during sudden pressure spikes or heavy shock loads. It ensures that the seal remains intact and functional without deformation, protecting the entire hydraulic system from catastrophic failure.
Installation & Application
This UN-type seal is typically installed in a closed housing groove for piston or rod sealing. It is widely used in hydraulic cylinders, excavators, forklifts, agricultural machinery, and pneumatic actuators. It is compatible with mineral-based hydraulic oils and operates effectively within a temperature range of -30°C to +100°C. Proper installation requires a clean environment and smooth groove edges to prevent damage to the sealing lips. When correctly installed, it provides long-lasting, reliable performance in demanding linear motion applications across various heavy-duty industries.
Difference from Skeleton Oil Seals
It is important to distinguish this product from TC skeleton oil seals. While TC oil seals are designed for high-speed rotary shafts (like motors and pumps), this UN U-cup seal is exclusively for low-speed reciprocating (linear) applications. Using the correct seal type is vital for preventing hydraulic system failure and fluid leakage. The PU material also offers superior abrasion resistance compared to the NBR used in standard oil seals. Choosing the right seal ensures optimal performance and extends the service life of your equipment.
Company Information
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