When an excavator’s hydraulic cylinder works under high temperature (above 100°C) for extended periods, standard oil seals often harden, crack, or lose elasticity, leading to oil leakage and equipment downtime. SANPING SEAL has launched its UNS Series oil seals – a solution specifically engineered to withstand continuous high-temperature operation up to 120°C while maintaining sealing pressure.

Why do hydraulic cylinders commonly experience oil seal failure under high temperatures?

Most standard oil seals use NBR (Nitrile Butadiene Rubber) material, which begins to degrade when temperatures exceed 100°C. For excavators working in hot environments or operating continuously for long shifts, three types of failures occur frequently:

• Hardening and cracking: High temperatures accelerate rubber aging, causing the lip to lose contact with the shaft
• Compression set: The seal fails to return to its original shape, creating a leakage path
• Lubricant breakdown:High heat degrades the grease behind the seal, increasing friction and wear

How does the SANPING SEAL UNS Series solve these problems?

The UNS Series oil seals feature three key improvements over conventional designs:

First, material upgrade. The UNS Series uses premium FKM (Viton®-compatible) compound, allowing continuous operation at 120°C without hardening – a significant improvement over standard NBR materials that fail above 100°C.

Second, optimized lip design. The hydrodynamic lip profile maintains the proper oil film on the shaft surface while effectively preventing external leakage, balancing both lubrication and sealing.

Third, stainless steel spring system. The garter spring is made of stainless steel, which maintains consistent lip pressure even under thermal expansion and contraction cycles, ensuring reliable sealing across varying temperatures.

Which excavator models are compatible with UNS Series oil seals?

The UNS Series covers standard hydraulic cylinder seal dimensions, making them compatible with major excavator brands including Caterpillar, Komatsu, Hitachi, Volvo, and SANY. For non-standard sizes, SANPING SEAL offers custom manufacturing with a 7–10 day lead time.

Where can you buy genuine SANPING SEAL UNS Series oil seals?

You can request a quote or sample directly through our website. Visit the UNS Series product page for technical datasheets, dimensional drawings, and application guidelines.

CTA:

Need a solution for your excavator’s hydraulic oil leakage? [Contact SANPING SEAL for a free UNS Series sample] – tell us your cylinder model and operating conditions, and we will recommend the right seal within 24 hours.