Polyurethane Seals
Polyurethane seals (also known as PU seals or urethane seals) are sealing components made from PU elastomer—a tough, flexible material that combines the resilience of rubber with the wear and impact resistance of plastic. They prevent leakage, reduce friction, and protect components in hydraulic, pneumatic, and mechanical systems.
Urethane Seals – High-Performance Sealing Solutions
Why Choose Polyurethane Seals?
- Polyurethane seals are ideal replacements for rubber or conventional seals that fail under pressure, abrasion, or fluid erosion. With superior tear and tensile strength, outstanding abrasion resistance, and excellent chemical and temperature durability, these seals extend service life, reduce replacement frequency, and minimize equipment downtime. Under dynamic loads, polyurethane seals can be 3–5 times more abrasion-resistant than comparable rubber seals.
- Additionally, polyurethane can be formulated in a range of hardness levels and customized to fit specific shaft, rod, or piston geometries. This flexibility makes polyurethane seals perfect for both custom applications and high-volume OEM production.
Application of Polyurethane Seals
- Hydraulic and pneumatic cylinders (rod seals, piston seals and wipers);
- Pumps, valves, compressors and fluid power systems;
- Construction, mining and off-road equipment;
- Industrial automation and motion systems;
- Marine and heavy-duty machinery where wear, oil exposure and motion are prevalent.
Custom Industrial Polyurethane Seals Solutions
- Product Specifications
- Gallery
Design & Dimensional Options of Polyurethane seals
| Design Parameter | Specification | Typical Range / Options |
| Inner Diameter (ID) | Matches shaft, rod, or piston | Fully customizable |
| Outer Diameter (OD) | Matches housing bore | Fully customizable |
| Seal Cross-Section | Standard or custom geometry | O-ring, X-ring, U-cup, lip seal, wiper/scraper, V-ring |
| Seal Profile Types | Static or dynamic applications | Rod seal, piston seal, rotary seal, static face seal, wiper seal, back-up ring |
| Hardness Options | Material hardness | 70A, 80A, 90A, 95A, 98A |
| Tolerance (Dimensional Precision) | Depends on process and size | ±0.02 mm to ±0.1 mm |
| Manufacturing Method | Depends on size & quantity | Cast PU, molded PU, machined PU |
| Color Options | Visual ID or OEM branding | Red, yellow, black, blue, natural, transparent |
| Surface Finish | Seal lip & body finish | Smooth, matte, polished sealing surface |
| Special Features | Optional design enhancements | Anti-extrusion rings, multi-lip geometry, reinforced backing, extended wear formulations |
Technical Date of PU seals
| Category | Specification | Typical Range / Description |
| Material | Polyurethane (PU / TPU / CPU) | High-performance elastomer for static & dynamic sealing |
| Hardness (Shore A) | 70–98 | Adjustable hardness for specific sealing force or flexibility |
| Tensile Strength | 20–55 MPa | High structural strength for high-pressure sealing |
| Elongation at Break | 300%–650% | Excellent elasticity for reciprocating and rotary seals |
| Tear Strength | 50–155 kN/m | Protects seal lips from tearing under stroke or pressure |
| Compression Set | <8% (22h × 70°C) | Ensures long-term dimensional recovery and sealing force |
| Abrasion Resistance | <0.05 cm³ / 1.61 km | Ideal for high-cycle hydraulic/pneumatic systems |
| Operating Temperature | -40°C to +120°C | Stable in extreme industrial environments |
| Chemical Resistance | Oils, fuels, hydraulic fluids, ozone, solvents | Suitable for hydraulic & industrial fluids |
| Coefficient of Friction | Low–Medium | Prevents heat buildup in dynamic seals |
Related Products
Polyurethane Seals Manufacturer
Lisen is a specialist manufacturer of polyurethane seals, offering complete sealing solutions—from custom molded or cast PU seals to standard production runs. Our engineering team assists with material selection, prototyping, and reliable volume supply for demanding industrial applications.
Whether you require custom polyurethane seals, industrial PU seals, or wear‑resistant hydraulic seals, our expertise ensures optimal performance, reduced downtime, and extended equipment life.
PU seals offer significantly higher tensile and tear strength, better abrasion resistance, and strong recovery from compression. While PTFE might offer extreme chemical resistance, PU often gives better wear performance in dynamic or high‑cycle environments.
Standard polyurethane seal grades typically handle temperatures from around ‑35 °C to +110 °C, and specialised grades can go lower or higher. They also perform well under high pressure when the proper formulation is chosen.
Yes — many polyurethane seal formulations resist oils, fuels and hydraulic fluids. However, as with any material, you should verify compatibility for your specific medium since certain solvents or chemicals can attack some PU grades.
The lifespan depends on operating conditions: pressure cycles, temperature extremes, chemical exposure, motion rate and installation quality. PU seals can significantly out‑last rubber equivalents in high‑wear applications when correctly specified.
Yes — although PU may cost more upfront than rubber, its higher wear resistance and longer service life typically reduce downtime and maintenance costs, making it cost‑effective for heavy‑duty or high‑cycle systems.