-251 BLUE FKM 75D O-RING

This o-ring is supplied in AS568-251 blue Viton® (FKM) 75 Shore A measuring an inside diameter of 5.109 in (129.77 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 5.387 in (136.83 mm), catalogued under part number V75MD251. It compresses into its gland to block fluid or gas migration across a joint.

As a material, Viton® (FKM) is valued for the industry benchmark where nitrile reaches its thermal limit and outstanding high-temperature capability. The material holds up against engine and transmission fluids, aromatic hydrocarbons, and petroleum oils and fuels. The material carries a published service range of -15°F (-26.1°C) to 400°F (204.4°C). Exposure to hot water and steam or low-molecular-weight organic acids will shorten service life.

This item meets FDA requirements for food contact, carries NSF listing, and is metal detectable for HACCP and foreign-body control programs. Maintenance and OEM teams specify it across high-temperature process equipment, aerospace, and automotive fuel systems.

Reference part number V75MD251 when ordering; the item is sold individually. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. 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.