Ordered as SV70212, this is an AS568-212 black Viton® (FKM) 70 Shore A Square-Cut Ring measuring an inside diameter of 0.859 in (21.82 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 1.137 in (28.88 mm). The square-cut ring seals with a broad flat contact band instead of the line contact of a round-section ring.
Viton® (FKM) is specified here for outstanding high-temperature capability and long service life in hot, chemically aggressive environments. The material holds up against chlorinated solvents, petroleum oils and fuels, and aggressive chemicals. Continuous operating temperature is published at -15°F (-26.1°C) to 400°F (204.4°C). It is not the right choice where low-molecular-weight organic acids or ketones and esters are present. The profile itself contributes a flat contact band that spreads sealing load across a wider area and simple lathe-cut manufacture at low tooling cost. Note that a square section is less suited to high-speed rotary service, where the larger contact area raises friction and heat.
Common environments for this compound include semiconductor equipment, high-temperature process equipment, and oil and gas.
This item is sold individually under part number SV70212. Nominal inside diameter is listed as 7/8 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.
description 568-212 FKM 75 SQUARE CUT RINGS
Actual_CS 0.139 inch (3.53 mm)
Actual_ID 0.859 inch (21.82 mm)
Actual_OD 1.137 inch (28.88 mm)
ProductCode Description O-Rings - Square/Quad - Commodity