Professional O-Ring and Oil Seal Manufacturer, Sealing Solution Supplier Since 2008.
PU UR U-Cup Seal - High-Quality Hydraulic Cylinder
Wear-Resistant Polyurethane Seal for Hydraulic Piston & Rod Reciprocation
Crafted from high-grade polyurethane, its precision U-shaped lip design ensures a tight, adaptive seal on pistons and rods during reciprocating motion—critical for leak-free performance in construction machinery, injection molders, and industrial hydraulic systems.
Core strengths:
- Superior wear resistance: Outlasts standard rubber seals, ideal for high-frequency motion.
- Robust durability: Withstands pressure fluctuations, reducing replacement needs.
- Versatile fit: Compatible with both piston and rod applications, simplifying inventory.
This seal doesn’t just seal—it enhances system efficiency, cuts maintenance downtime, and lowers long-term costs. Trust it for consistent, reliable performance in demanding hydraulic environments.
5.0
design customization
Please fill out the form below to request a quote or to request more information about us. Please be sure to upload customized requirement documents or pictures, and we will get back to you as soon as possible with a response. we're ready to start working on your new project, contact us now to get started.
Please fill out the form below to request a quote or to request more information about us. please be as detailed as possible in your message, and we will get back to you as soon as possible with a response. we're ready to start working on your new project, contact us now to get started.
Product Advantages
Exceptional Wear Resistance: Crafted from high-grade polyurethane, this seal exhibits 3-5 times better wear resistance compared to standard nitrile rubber seals. It can withstand the friction caused by high-frequency reciprocating motions of pistons and rods, significantly extending the service life of the sealing system.
Superior Pressure Resistance: The material's excellent mechanical strength enables it to handle working pressures up to 50MPa. Even under high-pressure conditions, it is not easily squeezed into gaps, effectively preventing leakage.
Strong Oil Resistance: It has good compatibility with various hydraulic oils such as mineral oil and synthetic oil, ensuring stable performance without swelling or hardening, thus maintaining reliable sealing.
Outstanding Elasticity and Recovery: The polyurethane material has excellent elasticity, allowing the U-shaped lip to tightly fit the sealing surface even with slight changes in the gap, ensuring a tight seal.
Long Service Life: Thanks to its wear resistance, pressure resistance, and oil resistance, the service life of this seal is greatly extended, reducing the frequency of replacement and maintenance, and lowering the overall cost.
Working Principle
The PU UR U-cup seal relies on its unique U-shaped cross-sectional design to achieve sealing. When installed in the hydraulic cylinder, the U-shaped lip is in contact with the piston or rod surface. Under the action of hydraulic medium pressure, the lip expands outward, increasing the contact pressure with the sealing surface, thereby achieving a tight seal. This self-tightening effect ensures that the sealing performance is better as the pressure increases. During the reciprocating movement of the piston or rod, the lip can adapt to the movement, maintaining continuous contact with the sealing surface and preventing medium leakage.
![PU UR U-Cup Seal - High-Quality Hydraulic Cylinder 7]()
Product Details
Material Quality: Adopts high-purity polyurethane raw materials with strict quality control to ensure stable material performance, free from impurities and bubbles.
Precision Manufacturing: Uses advanced molding technology, with precise control over the size of the cross-section (inner diameter, outer diameter, lip height) to ensure a perfect fit with the sealing groove. The dimensional tolerance is within ±0.05mm.
Lip Treatment: The lip is 经过 special polishing treatment, with a smooth surface and no burrs, reducing friction during movement and improving wear resistance.
Structural Design: The U-shaped structure is optimized, with reasonable thickness distribution of the lip and the bottom, ensuring both sealing performance and structural strength.
Surface Finish: The surface of the seal is smooth and flat, which is conducive to the flow of hydraulic medium and reduces resistance.
Application Range
This PU UR U-cup seal is widely used in various hydraulic systems that require reciprocating motion sealing, including but not limited to:
Construction machinery: Hydraulic cylinders of excavators, loaders, cranes, etc.
Industrial equipment: Hydraulic systems of injection molding machines, die-casting machines, hydraulic presses, etc.
Agricultural machinery: Hydraulic components of tractors, harvesters, etc.
Automobile industry: Hydraulic cylinders in automobile production lines and vehicle hydraulic systems.
Metallurgical industry: Hydraulic equipment in steel mills and smelters.
FAQ
Q: What is the temperature range applicable to this seal?
A: The standard temperature range is -20℃ to +100℃. For special high-temperature or low-temperature environments, Forever Seals can provide customized products with a temperature range of -40℃ to +120℃.
Q: Can this seal be used with water-based hydraulic fluids?
A: No, this seal is mainly designed for mineral oil and synthetic oil-based hydraulic fluids. For water-based hydraulic fluids, please choose Forever Seals' special seals for water-based media.
Q: How to determine the correct size when selecting?
A: You need to provide the inner diameter, outer diameter, and depth of the sealing groove, as well as the diameter of the piston or rod. Forever Seals' technical team will help you select the appropriate size.
Q: What is the service life of the seal under normal working conditions?
A: Under normal working conditions (appropriate pressure, temperature, and medium), the service life can reach 5000-10000 working hours, depending on the specific working environment.
Q: Can the seal be replaced with other types of seals?
A: It depends on the specific sealing groove design. If the groove size is compatible, it can be replaced with other U-cup seals of the same size, but it is recommended to consult Forever Seals' technical staff for confirmation.
Enterprise Selling Points
Professional R & D Team: Forever Seals boasts a professional R & D team with many years of experience in seal design and material research, which can continuously improve product performance and develop new products according to customer needs.
Strict Quality Control: From raw material procurement to production, testing, and packaging, Forever Seals implements strict quality control procedures. Each batch of products undergoes pressure testing, wear testing, and dimensional inspection to ensure qualified products leave the factory.
Customization Capability: Forever Seals can provide customized services according to customer's specific requirements (such as size, material, working environment, etc.) to meet the individual needs of different customers.
Efficient After-sales Service: Forever Seals has a professional after-sales service team to provide timely technical support and solutions for customer problems in the process of using products.
Advanced Production Equipment: Forever Seals adopts international advanced production equipment and production technology to ensure stable product quality and high production efficiency, and can meet the large demand of customers.
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