Which form of oil seal is used for high temperature and high pressure of oil cylinder

1.UHS oil seal is generally green, hardness is lower than UNS oil seal, for lower pressure environment;

2. UNS oil seal is generally blue, hardness is higher than UNS oil seal, for higher pressure environment.

UHS oil seal and UNS oil seal are polyurethane oil seal, mainly used in pressure cylinders, easy to install and can scrape dust adhesive to the piston rod. Polyurethane oil seal has good physical mechanical function, wear resistance function and oil resistance function. It is suitable for the most stringent working conditions. It avoids the entry of external impurities and thus achieves excellent sealing function. It is the most commonly used seal in medium-high pressure hydraulic cylinders.

Polyurethane is now the best functional insulation material in the world. The main chain contains a class of polymers-NHCOO-repeating structural units. English abbreviation PU. It is formed by polymerization of isocyanates(monomers) with hydroxyl compounds. Due to the strong polarity of carbamate groups, insoluble in Non-Polar groups, it has good oil resistance, patience, wear resistance, aging resistance and adhesion. Materials suitable for wider temperature scale(-50 ~ 150 °C) can be prepared with different raw materials, including elastomers, thermoplastic resins and thermosetting resins. It is not resistant to hydrolysis at high temperatures and it is not resistant to alkaline media.