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8-043 BLACK FKM 90D BACK-UP RING

Viton® Back-Up Ring, 3.489 in ID x 0.07 CS, 90A, Black, -15 to 400°F

Status
Out of Stock
Est. Ship Date
20 Oct 2026
Material
Fluoroelastomer (FKM/Viton)
Dash Size
43
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
1/16 inch
Nominal Inside Diameter
3 1/2 inch
Nominal Outside Diameter
3 5/8 inch
Unit of Measure
EA
SKU:
VBU90043

Product Specification

-
VBU90043 is an AS568-043 black Viton® (FKM) 90 Shore A Back-Up Ring supplied with an inside diameter of 3.489 in (88.62 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 3.629 in (92.18 mm). In service, this back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

Viton® (FKM) delivers the industry benchmark where nitrile reaches its thermal limit and very low compression set at elevated temperature. Expect good resistance to aromatic hydrocarbons, many acids, and petroleum oils and fuels. Continuous operating temperature is published at -15°F (-26.1°C) to 400°F (204.4°C). Verify compatibility before use with ketones and esters or amines.

It sees regular use in oil and gas, semiconductor equipment, and chemical processing.

Order part number VBU90043, sold individually. Nominal inside diameter is listed as 3 1/2 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.
Item
VBU90043
Description
8-043 BLACK FKM 90D BACK-UP RING
Actual Cross Section
0.07 inch (1.78 mm)
Actual Inside Diameter
3.489 inch (88.62 mm)
Actual Outside Diameter
3.629 inch (92.18 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6002
Product Category
O-Rings - Backup Rings