Greene, Tweed & Co. 4340 Series Back-Up Rings

Greene, Tweed’s new 43 back-up ring series has been specifically designed for use in AS5857 gland configurations as anti-extrusion devices in conjunction with O-rings, packings or other elastomeric seal types. A variety of high-performance materials can be provided and specifically targeted to meet the customer’s application requirements. This series provides a part numbering system for back-up rings per the Aerospace Industry specifications AS5860 and AS5861, which are appropriate for use in static glands according to AS5857. The materials shall consist of filled PTFE (polytetraflouroethy lene). The AS5860 specification is for scarf-cut (split) back-up rings while AS5861 is the specification for solid-type rings.