8-129 BLACK FKM 90D BACK-UP RING

Part number VBU90129 is an AS568-129 black Viton® (FKM) 90 Shore A Back-Up Ring built to an inside diameter of 1.549 in (39.34 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 1.755 in (44.58 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

The compound resists chlorinated solvents, petroleum oils and fuels, and aggressive chemicals. That behavior comes from the compound itself: Viton® (FKM) is widely chosen for long service life in hot, chemically aggressive environments and outstanding high-temperature capability. 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.

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

Reference part number VBU90129 when ordering; the item is sold individually. Unit weight is approximately 0.618 g and nominal inside diameter is listed as 1 9/16 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation.