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8-386 BLACK FKM 90D BACK-UP RING

Viton® Back-Up Ring, 16.955 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
386
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
17 inch
Nominal Outside Diameter
17 3/8 inch
Unit of Measure
EA
SKU:
VBU90386

Product Specification

-
VBU90386 is an AS568-386 black Viton® (FKM) 90 Shore A Back-Up Ring supplied with an inside diameter of 16.955 in (430.66 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 17.375 in (441.33 mm). In service, this 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) is specified here for excellent resistance to compression set and permeation, long service life in hot, chemically aggressive environments. The compound resists chlorinated solvents, many acids, and aromatic hydrocarbons. Continuous operating temperature is published at -15°F (-26.1°C) to 400°F (204.4°C).

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

Order part number VBU90386, sold individually. Nominal inside diameter is listed as 17 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application. For a size or compound outside the standard catalog, APG can quote from a print or sample.
Item
VBU90386
Description
8-386 BLACK FKM 90D BACK-UP RING
Actual Cross Section
0.21 inch (5.33 mm)
Actual Inside Diameter
16.955 inch (430.66 mm)
Actual Outside Diameter
17.375 inch (441.33 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6002
Product Category
O-Rings - Backup Rings