568-138 FKM 75 SQUARE CUT RINGS

This square-cut ring is supplied in AS568-138 black Viton® (FKM) 70 Shore A built to an inside diameter of 2.112 in (53.64 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 2.318 in (58.88 mm), catalogued under part number SV70138. It seals with a broad flat contact band instead of the line contact of a round-section ring.

This material stands up to chlorinated solvents, aggressive chemicals, and many acids. That behavior comes from the compound itself: Viton® (FKM) delivers outstanding high-temperature capability 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. It should not be specified for service in low-molecular-weight organic acids or hot water and steam. The profile itself contributes greater resistance to extrusion than a round section of the same size 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.

It sees regular use in automotive fuel systems, chemical processing, and oil and gas.

Stocked as SV70138 and sold individually. Nominal inside diameter is listed as 2 1/8 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application.