English - EN 
繁體 - ZH-TW 
简体 - ZH-CN 
Español - ES 
日本語 - JA 
العربية - AR 
Русский - RU 
Français - FR 
U-Cup
Categories : Rubber Products & Parts
U-Cups (U-rings) are versatile lip seals, named after their characteristic "U"-shaped cross-section. They are specifically engineered for reciprocating applications and serve as primary seals in hydraulic and pneumatic cylinders. Key Performance Benefits Pressure-Energized Sealing: The U-shape enables the sealing lips to expand against the hardware surface under system pressure. As the pressure increases, the sealing force proportionally grows, ensuring a reliable seal. Dual-Purpose Design: U-Cups function effectively as Rod Seals (preventing external leakage) and Piston Seals (preventing internal bypass between cylinder chambers). Optimized Friction: The lip geometry provides a secure seal with minimal contact area, reducing heat generation and mechanical wear during operation. Synergy with Back-up Rings High-Pressure Integrity: For systems operating above 5 MPa (50 bar), pairing a U-Cup with a back-up ring is essential to prevent material extrusion into clearance gaps. Structural Support: The back-up ring stabilizes the U-Cup in dynamic applications, particularly when large extrusion gaps or high-speed cycles are present. Common Industry Materials Polyurethane (PU): Offers superior abrasion resistance and high shear strength, ideal for heavy-duty hydraulic systems. Nitrile (NBR): Standard choice for pneumatic cylinders and lower-pressure environments. PTFE / POM: Often used for back-up rings to provide high-hardness support.
Rubber boot
Rubber dust boots are installed on automobiles and industrial equipment to protect screws, shafts, and other mechanical components. They prevent contaminants such as oil, water, dust, acids, alkalis, and other harmful substances from entering the screws, shafts, or mechanisms, ensuring smooth operation and prolonging equipment lifespan. These boots are essential for maintaining reliable performance in demanding environments.
Bonded seal
A bonded seal is a hybrid sealing component that combines a metal washer with an elastomeric sealing ring bonded to its inner diameter. This design creates a reliable, leak-proof seal around bolts, screws, and flanged connections in static applications such as hydraulic and pneumatic systems. Originally developed by the Dowty Group, these seals are also commonly known as Dowty seals or bonded washers.