O-rings are ring-shaped sealing elements with a circular cross-section that are widely used in sealing technology. They are used to seal static and dynamic joints against liquids and gases. Their function is based on the elastic deformation of the material, which reliably closes the gap between two components.
Fietz offers O-rings made of PTFE (FiKumer^®-F), polyurethane (FiPur^®), and elastomer (FiLomer^®). Depending on the customer’s application and the media involved, Fietz can select the right material from its extensive portfolio.

 

PTFE O-Rings – FiKumer^®-F  

PTFE is a thermoplastic with excellent chemical and thermal resistance
• Properties: virtually universal chemical resistance, very low coefficient of friction, high temperature resistance (−200 °C to +260 °C)
• Advantages: ideal for aggressive chemicals, high temperatures and dry media; no aging
• Disadvantages: no elasticity – PTFE O-rings often need to be pre-stressed or designed as composite seals (e.g., PTFE with an elastomer core)
• Applications: low-pressure hydraulics, chemical industry, food processing, vacuum technology

Polyurethane O-rings – FiPur^® 

Polyurethane combines high mechanical strength with good elasticity
• Properties: high abrasion resistance, good elasticity, good resistance to oils and greases. FiPur® materials are highly resistant to hydrolysis
• Advantages: particularly durable in dynamic applications, resistant to extrusion and wear
• Disadvantages: limited chemical resistance, sensitive to hot water and steam
• Applications: hydraulic cylinders, mobile hydraulics, applications subject to high pressure or movement

Elastomer O-rings – FiLomer^®

Elastomers (NBR, EPDM, FKM, FFKM) are the most commonly used materials for O-rings
• Properties: high elasticity, good resilience, wide range of temperature and media resistance
• Advantages: good sealing performance due to elastic behavior, cost-effective, easy to install
• Disadvantages: limited chemical resistance, not suitable for extreme temperatures or aggressive media
• Applications: hydraulics, pneumatics, automotive fluid systems, general mechanical engineering applications