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Danfoss / Eaton BACK-UP Ring

Description & Features

Made from Teflon, this back-up ring is a precision sealing component designed to support and retain primary seals in hydraulic assemblies, preventing extrusion under pressure cycling. Part of the Aeroquip line from Danfoss / Eaton, the Danfoss / Eaton Back-Up Ring is available in a variety of sizes to accommodate different fitting and port configurations across hydraulic systems.

Teflon construction provides strong chemical resistance and reliable performance across a broad range of fluid types. At 0.01 lb, this is a lightweight replacement part well suited for maintenance and repair kits. Fluid compatibility documentation is available through Eaton for reference when specifying this component for a particular application.

SKU: 22021-6

Supplier Part Number (MPN): 22021-6

Specifications

Brand Aeroquip® by Danfoss	Dimensions 0.853 in OD x 0.03 in THK	Fitting Type Back-Up Ring	Material PTFE	Material Construction PTFE	nmfc 50	Series 22021 Series

Product Questions & Answers (1)

Question by: Cody M on Nov 2, 2025, 4:42 PM

What's the deal with this ring, is it just a regular washer?

Answer by: Customer Support on Nov 4, 2025, 8:41 AM

Not quite a regular washer, it's made from Teflon and specifically designed as a back-up to your primary seals in hydraulic systems. Basically, it keeps those seals from getting squeezed out of place when the pressure spikes.