Back-up Rings are protective and supporting elements with no
sealing function. Made from extrusion-resistant materials ,and they
usually have a rectangular cross section and are installed in a
groove with an elastomer O-Ring. Due to their tight fit in the
housing, Back-up Rings prevent extrusion of the pressurized
elastomer sealing element into the clearance or extrusion gap.
Using Back-up Rings allows O-Rings to be utilized in higher
pressure applications, where larger extrusion gaps are required and
where there are reciprocating or rotating movements. They also
compensate for large temperature fluctuations.
