Part number VBU90170 is an AS568-170 black Viton® (FKM) 90 Shore A Back-Up Ring built to an inside diameter of 7.737 in (196.52 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 7.943 in (201.75 mm). A back-up ring bridges the extrusion gap so the primary seal holds its shape under load.
The material holds up against many acids, aggressive chemicals, and aromatic hydrocarbons. Viton® (FKM) is known for long service life in hot, chemically aggressive environments and very low compression set at elevated temperature. The material carries a published service range of -15°F (-26.1°C) to 400°F (204.4°C). It should not be specified for service in low-molecular-weight organic acids or amines.
Maintenance and OEM teams specify it across oil and gas, aerospace, and semiconductor equipment.
This item is sold individually under part number VBU90170. Application requirements vary, so validate compatibility with your process conditions prior to installation. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.
description 8-170 BLACK FKM 90D BACK-UP RING
Actual_CS 0.103 inch (2.62 mm)
Actual_ID 7.737 inch (196.52 mm)
Actual_OD 7.943 inch (201.75 mm)
ProductCode Description O-Rings - Backup Rings