4 – BACK-UP RINGS 4-1 DESCRIPTION The anti-extrusion rings, also known as back-up rings are used in dynamic or static sealing rods or pistons applications. Under high pressures they prevent the penetration (gap extrusion) of the sealing element (O-Ring or X-Ring) in the sealing gap. 4-2 ADVANTAGES In addition to improving the lifetime of an O-ring or a X-ring by protecting them from any impurities, the use of anti-extrusion rings widens their range of applications while remaining very cost effective in the following cases : - Pressure >50 bars - Large tolerances and radial clearance - High speed - Pressure changes - Wide temperature influences 4-3 BACK-UP RING VERSIONS There are 3 standard profiles of back-up rings (BAE) : AES : Back-up ring, spiral form AEM : Back-up ring, unslotted AEC : Back-up ring, concave The profiles AEM and AEC are available in slotted design with an angle of 30 or 45°, or special version (20°) upon request.

■ Back-up ring type AES - Rectangular cross section - Material: PTFE - Cut angle at 30° or 45 ° - Static and dynamic use - For reciprocating movements only - Installation in closed grooves - Can be adjusted by simple cuts in the case of non standard diameters - Compensation of large temperature changes and tolerances through a screw-like elongation and contraction. ■ Back-up ring type AEM - Rectangular cross section - Material : virgin or filled PTFE-PU-PA-NBR90 - Reciprocating and rotating movements possible - Installation in open grooves (possible in closed grooves for the type AEMF Cut angle...

4-6-2 Back-up rings type AEC in accordance with AS568A

4 - BACK-UP RINGS Item number

4 - BACK-UP RINGS Item number

4 - BACK-UP RINGS STAC EM V. _ _V .y Item number