Ordered as VBU90167, this is an AS568-167 black Viton® (FKM) 90 Shore A Back-Up Ring measuring an inside diameter of 6.987 in (177.47 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 7.193 in (182.7 mm). The back-up ring bridges the extrusion gap so the primary seal holds its shape under load.
As a material, Viton® (FKM) is valued for the industry benchmark where nitrile reaches its thermal limit, excellent resistance to compression set and permeation. The material holds up against many acids, chlorinated solvents, and petroleum oils and fuels. The material carries a published service range of -15°F (-26.1°C) to 400°F (204.4°C). It is not the right choice where hot water and steam or low-molecular-weight organic acids are present.
You will find this material specified across high-temperature process equipment, aerospace, and oil and gas.
Order part number VBU90167, sold individually. Nominal inside diameter is listed as 7 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.
description 8-167 BLACK FKM 90D BACK-UP RING
Actual_CS 0.103 inch (2.62 mm)
Actual_ID 6.987 inch (177.47 mm)
Actual_OD 7.193 inch (182.7 mm)
ProductCode Description O-Rings - Backup Rings