Back-up Rings

Reliably Prevent Gap Extrusion

Back-up rings do not have a sealing function but are used to prevent gap extrusion. They can be used in combination with O-rings or X-rings, both for static and dynamic loads. Back-up rings prevent the seal from extruding into the sealing gap and thus enable sealing of higher media pressures. They are often used in applications with pulsating or varying pressures, such as hydraulic valves and pumps, cylinder bases and heads.

Benefits at a Glance

Prevent gap extrusion
Combinable with O-rings or X-rings
Different product variants to fit your application
Good lifetime
Very good price-performance ratio
Suitable for many industrial applications

Important note: Dichtomatik products comply with common industrial standards and therefore are suitable for many applications excluding safety-critical ones like Automotive. Premium Freudenberg products are the right choice for all applications ensuring highest quality and safety standards and therefore optimal total cost of ownership.

Choose the Right Product

Out of a Three Types

STR END (endless) and STR GS (30° slotted) made of POM
(temp.: -50 to +90 °C) for use in mineral oils, fats and pressure media HFA, HFB, HFC
STR END (endless) STR GS (30° slotted) made of PTFE
(temp.: -200 to +260 °C) shows broad resistance to acids, bases, alcohols, oils and pressure fluids
STU (endless with concave molding) made of NBR
(temp.: -30 to +100 °C) for use in hydraulic oils, mineral-oil based lubricants, non-flammable hydraulic pressure fluids (max. +50 °C) and water (max. +80 °C)