Hydraulic seals

Hydraulic seals

Hydraulic seals operate under conditions of high pressure, high sliding speed and changing temperatures. Proper seal material selection must take into account system operating parameters, the type of working fluid and the service environment. Seal quality directly affects the tightness, durability and performance of a hydraulic cylinder.

Basic sealing materials

• PU (polyurethane): very good elasticity, high abrasion resistance and mechanical strength. Used in lip seals, piston seals and wipers.
• PTFE: low friction coefficient, high chemical resistance and a wide operating temperature range. Resistant to most hydraulic media.
• POM: low friction coefficient, low moisture absorption, high stiffness and dimensional stability. Used in guide and back-up rings.
• TPE: an elastomer combining the properties of rubber and plastic. It offers high elasticity and resistance to weather conditions.
• NBR: good abrasion resistance, resistance to permanent deformation and high tensile strength.
• FKM / FPM: resistance to high temperatures, hydrocarbons and chemically aggressive media.
• Fabric with nitrile elastomer: high resistance to deformation, abrasion and atmospheric factors.

Sealing system in a hydraulic cylinder

The sealing system of a hydraulic cylinder includes piston seals, rod seals, wipers and guide rings. Guide rings prevent metal-to-metal contact, stabilize linear movement and reduce wear of working components.

The correct configuration of the sealing set is essential for reliable hydraulic system operation, seal durability and maintaining proper tightness of the entire cylinder.