Anti-extrusion rings (back-up rings) are used for static and dynamic applications in connection with O-rings, to prevent extrusion of the O-ring into the diametral clearance. The sizes of X1 anti-extrusion rings conform to AS8791 which
specifies the dimensional and material engineering requirements for PTFE back-up rings used in aerospace applications. The standard material is Polon® 001 (virgin PTFE).
• Insensitive to pressure peaks.
• High extrusion resistance.
• Excellent media resistance in case of suitable compound selection.
• Any desired nominal diameter available due to manufacturing technology.
• Installation in closed and undercut housings.
We recommend to specify back-up rings when at least one of the following working conditions is present in cases where the intention is to seal with O-rings only:
• Pressure above 70 bar.
• Diametral clearance exceeding 0.25 mm at p > 10 bar.
• High stroke frequency.
• High temperatures.
• Contaminated medium.
• Strong pressure pulsing or pressure changes.
