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8-369 BLACK FKM 90D BACK-UP RING

Viton® Back-Up Ring, 7.975 in ID x 0.21 CS, 90A, Black, -15 to 400°F

Status
Out of Stock
Est. Ship Date
20 Oct 2026
Material
Fluoroelastomer (FKM/Viton)
Dash Size
369
Durometer
90 Shore A
Cross Section Type
Round
Color
Black
Minimum Temperature
-15°F (-26°C)
Maximum Temperature
400°F (204°C)
Nominal Cross Section
3/16 inch
Nominal Inside Diameter
8 inch
Nominal Outside Diameter
8 3/8 inch
Unit of Measure
EA
SKU:
VBU90369

Product Specification

-
Ordered as VBU90369, this is an AS568-369 black Viton® (FKM) 90 Shore A Back-Up Ring supplied with an inside diameter of 7.975 in (202.57 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 8.395 in (213.23 mm). The back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

As a material, Viton® (FKM) is known for the industry benchmark where nitrile reaches its thermal limit and long service life in hot, chemically aggressive environments. This material stands up to engine and transmission fluids, many acids, and aggressive chemicals. The material carries a published service range of -15°F (-26.1°C) to 400°F (204.4°C). Verify compatibility before use with low-molecular-weight organic acids or ketones and esters.

Typical settings include chemical processing, high-temperature process equipment, and oil and gas.

Order part number VBU90369, sold individually. Nominal inside diameter is listed as 8 inch. Review your operating media and conditions against this specification before installation. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.
Item
VBU90369
Description
8-369 BLACK FKM 90D BACK-UP RING
Actual Cross Section
0.21 inch (5.33 mm)
Actual Inside Diameter
7.975 inch (202.57 mm)
Actual Outside Diameter
8.395 inch (213.23 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6002
Product Category
O-Rings - Backup Rings