APG stocks the VBU90007, an AS568-007 black Viton® (FKM) 90 Shore A Back-Up Ring built to an inside diameter of 0.145 in (3.68 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 0.285 in (7.24 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.
The material holds up against aromatic hydrocarbons, aggressive chemicals, and many acids. That behavior comes from the compound itself: Viton® (FKM) is widely chosen for excellent resistance to compression set and permeation, outstanding high-temperature capability. Service temperature is rated from -15°F (-26.1°C) through 400°F (204.4°C). Applications involving low-molecular-weight organic acids or amines call for a different compound.
It sees regular use in chemical processing, semiconductor equipment, and high-temperature process equipment.
Stocked as VBU90007 and sold individually. Nominal inside diameter is listed as 5/32 inch. Review your operating media and conditions against this specification before installation.
description 8-007 BLACK FKM 90D BACK-UP RING
Actual_CS 0.07 inch (1.78 mm)
Actual_ID 0.145 inch (3.68 mm)
Actual_OD 0.285 inch (7.24 mm)
ProductCode Description O-Rings - Backup Rings