Seals

O-rings in normal or quenched design in over 200 sizes from 0.6 mm inner diameter to 500 mm outer diameter in any cord size.

Solid O-rings made of pure or modified PTFE are used for static sealing of aggressive or hot media and are used wherever elastomer O-rings behave critically or fail completely. The excellent chemical and physical properties of PTFE materials guarantee long-lasting and maintenance-free function, even under extreme conditions.

PTFE O-rings are also used as sealing elements for slow movements. Here they offer the advantage of low friction losses due to the non-existent stick-slip effect.

In the above-mentioned applications and in the case of large temperature differences, it should be noted that the considerably lower elasticity of the PTFE O-ring compared to elastomer O-rings must be compensated for by additional mechanical contact pressure. The prerequisite for this is that the O-ring is well chambered in order to prevent the material-related tendency to cold flow.

An increase in elasticity can be achieved by thermal/chemical post-treatment (quenching) or constructive measures (design with grooves in the circumferential direction), whereby different types are available for the latter design depending on the application.

   

Materials

O-rings from Fietz are made of pure PTFE as standard. For special applications, the material can be modified with fillers to optimise certain properties.