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8-368 BLACK FKM 90D BACK-UP RING

Viton® Back-Up Ring, 7.725 in ID x 0.21 CS, 90A, Black, -15 to 400°F

Status
Out of Stock
Est. Ship Date
21 Oct 2026
Material
Fluoroelastomer (FKM/Viton)
Dash Size
368
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
7 3/4 inch
Nominal Outside Diameter
8 1/8 inch
Unit of Measure
EA
SKU:
VBU90368

Product Specification

-
Ordered as VBU90368, this is an AS568-368 black Viton® (FKM) 90 Shore A Back-Up Ring measuring an inside diameter of 7.725 in (196.22 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 8.145 in (206.88 mm). The back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

Viton® (FKM) delivers outstanding high-temperature capability and the industry benchmark where nitrile reaches its thermal limit. It resists engine and transmission fluids, aggressive chemicals, and many acids. Continuous operating temperature is published at -15°F (-26.1°C) to 400°F (204.4°C).

Maintenance and OEM teams specify it across chemical processing, automotive fuel systems, and oil and gas.

VBU90368 ships individually. Nominal inside diameter is listed as 7 3/4 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application.
Item
VBU90368
Description
8-368 BLACK FKM 90D BACK-UP RING
Actual Cross Section
0.21 inch (5.33 mm)
Actual Inside Diameter
7.725 inch (196.22 mm)
Actual Outside Diameter
8.145 inch (206.88 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6002
Product Category
O-Rings - Backup Rings