Key points for using seals

(1) Select appropriate seal materials and hydraulic oil, ensuring compatibility with the operating temperature and oil.  

(2) The service life of seals can be extended by improving the geometric accuracy (concentricity) of the sliding parts, 

using high-quality materials (such as hard chrome plating), and maintaining a fine surface roughness.  

① For oil seals used on the shaft necks of hydraulic pumps and motors, 

the surface roughness of the sliding contact area should be Ra 0.25 μm or less, and the surface should be hard chrome-plated. 

In practical applications, the radial spring force of the seal lip should be adjusted appropriately to ensure proper tightness. 

During installation, a sleeve or thin spacer should be used to protect the sealing ring and prevent lip rolling, twisting, 

or spring dislodgment.  

② The inner surface of hydraulic cylinder barrels is often finished by roller burnishing, 

which not only improves surface roughness but also induces cold working to enhance hardness, 

thereby extending the service life of sealing rings. Additionally, factors such as operating pressure, 

sliding surface length, and seal type also significantly affect service life. Therefore, 

inspection intervals should be determined based on these conditions.  

③ Maintaining good lubrication on sealing surfaces and preventing contamination are essential. 

The use of oil that meets specified cleanliness standards and proper installation methods are also critical requirements.