{"product_id":"391-viton-o-ring-75a-22-in-id-durable-chemical-fuel-seal","title":"391 Viton O-Ring 75A, 22 in ID - Durable Chemical \u0026 Fuel Seal","description":"\u003cp\u003eIn this review the 391 Viton O-ring is evaluated as a straightforward replacement seal for applications that demand chemical and heat resistance. The bottom line: this pack of five 75A durometer O-rings is best for technicians and hobbyists who need reliable, compact seals for fuel systems, hydraulic fittings, and equipment exposed to high temperatures. Its main selling point is material performance - made from Viton fluorocarbon elastomer, these O-rings resist a wide range of fuels and chemicals while maintaining form and sealing ability across a large temperature span.\u003c\/p\u003e\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Viton fluorocarbon elastomer offers broad chemical and fuel resistance for demanding service environments.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTemperature range:\u003c\/strong\u003e Rated for use from -15 degrees F to 400 degrees F, making it suitable for high-heat and low-temperature applications.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHardness:\u003c\/strong\u003e 75A durometer provides a balance of resilience and penetration resistance for durable sealing under pressure.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShape and fit:\u003c\/strong\u003e Round cross-section seals between overlapping cylindrical surfaces to prevent leaks in common plumbing and fuel fixtures.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStandards:\u003c\/strong\u003e Manufactured to AS568A sizes, which simplifies replacement and compatibility with many standard fittings.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePack quantity:\u003c\/strong\u003e Supplied as a pack of five, giving you spares for maintenance or multiple installations.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eWho It's For\u003c\/h2\u003e\n\u003cp\u003eThe 391 Viton O-ring is well suited to maintenance technicians, gunsmiths, and DIYers who need an O-ring that handles fuels, aromatic and aliphatic hydrocarbons, silicone oils, and many chlorinated solvents without rapid degradation. It is a practical choice for replacing worn seals in fuel bottles, firearm barrel interfaces, and vacuum equipment.\u003c\/p\u003e\n\u003cp\u003eThose who should look elsewhere include users requiring compatibility with strong alkalis, amines, glycol-based brake fluids, or super-heated steam, since Viton is vulnerable to those chemistries. If a softer or very low-temperature compound is required, a different elastomer may be a better fit.\u003c\/p\u003e\n\u003ch2\u003ePros \u0026amp; Cons\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003ePros\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eExcellent resistance to fuels and many chemicals, so it holds up where other elastomers fail.\u003c\/li\u003e\n\u003cli\u003eWide usable temperature range from -15 degrees F to 400 degrees F for versatile service.\u003c\/li\u003e\n\u003cli\u003e75A durometer gives a durable, leak-resistant seal that customers report fits well in common replacement roles.\u003c\/li\u003e\n\u003cli\u003eSold in packs of five, offering value and spare parts for routine maintenance.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eCons\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eNot compatible with low molecular organic acids, some amines, alkalis, and glycol-based brake fluids, which limits use in some chemical systems.\u003c\/li\u003e\n\u003cli\u003e75A hardness may be firmer than desired for extremely delicate sealing interfaces needing softer material.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaterial\u003c\/td\u003e\n\u003ctd\u003eViton (fluorocarbon elastomer)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eColor\u003c\/td\u003e\n\u003ctd\u003eBlack\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInner diameter\u003c\/td\u003e\n\u003ctd\u003e22 in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOuter diameter\u003c\/td\u003e\n\u003ctd\u003e22-3\/8 in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCross-section width\u003c\/td\u003e\n\u003ctd\u003e3\/16 in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDurometer\u003c\/td\u003e\n\u003ctd\u003e75A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature range\u003c\/td\u003e\n\u003ctd\u003e-15 degrees F to 400 degrees F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003ch2\u003eOur Verdict\u003c\/h2\u003e\n\u003cp\u003eThe 391 Viton O-ring is a practical, value-minded choice for anyone needing a resilient seal compatible with a broad range of fuels and chemicals. For routine maintenance on fuel bottles, pneumatic fittings, or high-heat fixtures it delivers durable leak resistance and sensible longevity, provided the excluded chemistries are avoided.\u003c\/p\u003e\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eWill this O-ring work with gasoline and diesel?\u003c\/strong\u003e\u003cbr\u003eYes, Viton is compatible with many fuels, including aromatic and aliphatic hydrocarbons, making it suitable for gasoline and diesel applications.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I use these O-rings with brake fluid?\u003c\/strong\u003e\u003cbr\u003eNo, Viton is not recommended for glycol-based brake fluids; those fluids can degrade Viton over time.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAre these standard sizes easy to replace?\u003c\/strong\u003e\u003cbr\u003eYes, these O-rings conform to AS568A sizing conventions, so they fit many common standard fittings and replacement roles.\u003c\/p\u003e","brand":"Mr O-Ring","offers":[{"title":"Default Title","offer_id":48196827185371,"sku":"B000FOI2D8","price":160.59,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0724\/1043\/1707\/files\/81iyYJCP7YL._SL1500_ec47e0fe-b18b-43b9-a5c8-e3aec6c073a3.jpg?v=1770274784","url":"https:\/\/gearmusthave.com\/products\/391-viton-o-ring-75a-22-in-id-durable-chemical-fuel-seal","provider":"GearMustHave","version":"1.0","type":"link"}