568-237 FKM 75 SQUARE CUT RINGS

This square-cut ring is supplied in AS568-237 black Viton® (FKM) 70 Shore A built to an inside diameter of 3.359 in (85.32 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 3.637 in (92.38 mm), catalogued under part number SV70237. It resists the spiral failure that affects round rings on long reciprocating strokes.

It resists petroleum oils and fuels, aromatic hydrocarbons, and many acids. That behavior comes from the compound itself: Viton® (FKM) is specified for the industry benchmark where nitrile reaches its thermal limit and long service life in hot, chemically aggressive environments. Continuous operating temperature is published at -15°F (-26.1°C) to 400°F (204.4°C). The profile itself contributes simple lathe-cut manufacture at low tooling cost and a rectangular section that will not roll in the groove. Note that a square section is less suited to high-speed rotary service, where the larger contact area raises friction and heat.

It sees regular use in high-temperature process equipment, aerospace, and chemical processing.

Order part number SV70237, sold individually. Nominal inside diameter is listed as 3 3/8 inch. Review your operating media and conditions against this specification before installation. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.