8-352 BLACK FKM 90D BACK-UP RING

Ordered as VBU90352, this is an AS568-352 black Viton® (FKM) 90 Shore A Back-Up Ring with an inside diameter of 4.85 in (123.19 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 5.27 in (133.86 mm). The back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

It resists chlorinated solvents, aggressive chemicals, and engine and transmission fluids. Viton® (FKM) is valued for very low compression set at elevated temperature, excellent resistance to compression set and permeation. Rated temperature range runs from -15°F (-26.1°C) to 400°F (204.4°C) in continuous service. It is not the right choice where amines or hot water and steam are present.

Maintenance and OEM teams specify it across high-temperature process equipment, automotive fuel systems, and oil and gas.

This item is sold individually under part number VBU90352. 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.