This o-ring is supplied in AS568-421 black Viton® (FKM) 75 Shore A built to an inside diameter of 3.975 in (100.97 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 4.525 in (114.94 mm), catalogued under part number V70421. It seats in a machined groove and forms a leak-tight barrier when compressed between two mating surfaces.
This material stands up to aromatic hydrocarbons, aggressive chemicals, and petroleum oils and fuels. Viton® (FKM) is specified for very low compression set at elevated temperature and long service life in hot, chemically aggressive environments. Rated temperature range runs from -15°F (-26.1°C) to 400°F (204.4°C) in continuous service. Exposure to low-molecular-weight organic acids or amines will shorten service life.
You will find this material specified across high-temperature process equipment, aerospace, and chemical processing.
Reference part number V70421 when ordering; the item is sold individually. Unit weight is approximately 23.29 g and nominal inside diameter is listed as 4 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.
description -421 BLACK FKM 75D O-RING
uf_description2 0.275" (6.99MM) CS X 3.975" (100.97MM) ID
Actual_CS 0.275 inch (6.99 mm)
Actual_ID 3.975 inch (100.97 mm)
Actual_OD 4.525 inch (114.94 mm)
ProductCode Description O-Rings - Bulk - Commodity