8-125 BLACK FKM 90D BACK-UP RING

This back-up ring is supplied in AS568-125 black Viton® (FKM) 90 Shore A with an inside diameter of 1.299 in (32.99 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 1.505 in (38.23 mm), catalogued under part number VBU90125. It allows a standard o-ring to operate at higher pressures than it could unsupported.

The compound resists petroleum oils and fuels, aromatic hydrocarbons, and chlorinated solvents. That behavior comes from the compound itself: Viton® (FKM) delivers very low compression set at elevated temperature and outstanding high-temperature capability. Published continuous service range is -15°F (-26.1°C) to 400°F (204.4°C). It is not the right choice where amines or low-molecular-weight organic acids are present.

Typical settings include automotive fuel systems, aerospace, and chemical processing.

Reference part number VBU90125 when ordering; the item is sold individually. Unit weight is approximately 0.527 g. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.