568-169 FKM 75 SQUARE CUT RINGS

APG stocks the SV70169, an AS568-169 black Viton® (FKM) 70 Shore A Square-Cut Ring built to an inside diameter of 7.487 in (190.17 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 7.693 in (195.4 mm). A square-cut ring seals with a broad flat contact band instead of the line contact of a round-section ring.

It resists many acids, engine and transmission fluids, and petroleum oils and fuels. That behavior comes from the compound itself: Viton® (FKM) is valued for excellent resistance to compression set and permeation, very low compression set at elevated temperature. Service temperature is rated from -15°F (-26.1°C) through 400°F (204.4°C). Applications involving ketones and esters or low-molecular-weight organic acids call for a different compound. The profile itself contributes simple lathe-cut manufacture at low tooling cost and a flat contact band that spreads sealing load across a wider area. 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, high-temperature process equipment, and aerospace.

This item is sold individually under part number SV70169. Nominal inside diameter is listed as 7 1/2 inch. Check the compound against your process media, pressure and temperature before committing to a design.