Use item VBU90437 when a FKM Viton 90A Backup Ring is required for anti-extrusion support behind O-rings in high-pressure hydraulic and pneumatic glands. The item is specified by AS568-437; 5.975 inch (151.77 mm) ID x 0.275 inch (6.99 mm) CS; 6.525 inch (165.74 mm) OD, with 6 inch nominal ID; 1/4 inch nominal CS for cross-reference against common gland and replacement dimensions. The FKM/Viton fluoroelastomer construction supports high-temperature service, fuels, lubricants and many chemical sealing environments. It is with a listed temperature range of -15°F (-26°C) to 400°F (204°C), which can help narrow material selection for heat, cold or process exposure. The black color and round profile provide a practical visual identifier during receiving, stocking and installation. As a backup ring, it works with a primary O-ring to help limit extrusion into clearance gaps under pressure. The each-unit format supports precise replacement, kitting, resale and job-specific purchasing. Important product identifiers include O-rings, replacement seals, fluid sealing, material compatibility and dimensional fit. It supports customer comparison, distributor cataloging and specification-based selection without relying on pricing, availability or shipping claims.
description 8-437 FLUOROELASTOMER 90 B/U RING
Actual_CS 0.275 inch (6.99 mm)
Actual_ID 5.975 inch (151.77 mm)
Actual_OD 6.525 inch (165.74 mm)
ProductCode Description O-Rings - Backup Rings