This back-up ring is supplied in AS568-315 black Viton® (FKM) 90 Shore A measuring an inside diameter of 0.787 in (19.99 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 1.207 in (30.66 mm), catalogued under part number VBU90315. It extends o-ring service life by supporting the seal against extrusion under high pressure.
It resists aggressive chemicals, many acids, and chlorinated solvents. That behavior comes from the compound itself: Viton® (FKM) is valued for outstanding high-temperature capability and very low compression set at elevated temperature. Published continuous service range is -15°F (-26.1°C) to 400°F (204.4°C). It is not the right choice where ketones and esters or amines are present.
It sees regular use in automotive fuel systems, aerospace, and semiconductor equipment.
Reference part number VBU90315 when ordering; the item is sold individually. Check the compound against your process media, pressure and temperature before committing to a design. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.
description 8-315 BLACK FKM 90D BACK-UP RING
Actual_CS 0.21 inch (5.33 mm)
Actual_ID 0.787 inch (19.99 mm)
Actual_OD 1.207 inch (30.66 mm)
ProductCode Description O-Rings - Backup Rings