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8-204 BLACK FKM 90D BACK-UP RING

Viton® Back-Up Ring, 0.359 in ID x 0.139 CS, 90A, Black, -15 to 400°F

Status
Out of Stock
Est. Ship Date
20 Oct 2026
Material
Fluoroelastomer (FKM/Viton)
Dash Size
204
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
1/8 inch
Nominal Inside Diameter
3/8 inch
Nominal Outside Diameter
5/8 inch
Unit of Measure
EA
SKU:
VBU90204

Product Specification

-
The VBU90204 is an AS568-204 black Viton® (FKM) 90 Shore A Back-Up Ring with an inside diameter of 0.359 in (9.12 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 0.637 in (16.18 mm). This back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

As a material, Viton® (FKM) is specified for excellent resistance to compression set and permeation, long service life in hot, chemically aggressive environments. Expect good resistance to aromatic hydrocarbons, chlorinated solvents, and engine and transmission fluids. Rated temperature range runs from -15°F (-26.1°C) to 400°F (204.4°C) in continuous service. Exposure to ketones and esters or amines will shorten service life.

It sees regular use in semiconductor equipment, high-temperature process equipment, and chemical processing.

VBU90204 ships individually. As always, verify media compatibility and operating conditions against the requirements of your specific application. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
Item
VBU90204
Description
8-204 BLACK FKM 90D BACK-UP RING
Actual Cross Section
0.139 inch (3.53 mm)
Actual Inside Diameter
0.359 inch (9.12 mm)
Actual Outside Diameter
0.637 inch (16.18 )
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6002
Product Category
O-Rings - Backup Rings