447 Viton O-Ring 75A Durometer, 9 in ID - Durable Chemical Seal

In this review the 447 Viton O-ring is judged on durability, chemical resistance, and fit for common replacement tasks. It is best suited for technicians, hobbyists, and equipment owners who need a robust seal that withstands heat and many fuels; the single biggest reason to buy is the material - Viton fluorocarbon elastomer - which gives proven resistance to fuels, aromatic and aliphatic hydrocarbons, ozone, and weathering while holding shape at high temperature.

Key Features

• Material: Made of Viton, the elastomer offers superior resistance to many chemicals and fuels compared with standard rubbers.
• Temperature range: Rated for -15 degrees F to 400 degrees F, it stays functional across broad service temperatures encountered in engines and industrial equipment.
• Shape and seal: The round cross-section provides a reliable seal between cylindrical overlapping surfaces, reducing leaks when installed correctly.
• Hardness: A shore durometer of 75A balances firmness and compressibility for resistance to penetration while still forming an effective gasket under compression.
• Standards: Meets Aerospace Standard AS568A sizing conventions, which helps when replacing O-rings in equipment that references common O-ring dimensions.
• Compatibility: Works with non-flammable hydraulic fuels, silicone oils, chlorinated hydrocarbons, and many hydrocarbon fuels, making it versatile for maintenance tasks.

Who It's For

This O-ring is aimed at users needing a dependable replacement for equipment exposed to heat and fuels: for example, those servicing fuel bottles, barrel seals, switchback components, or other cylindrical fittings where leak resistance is expected. Mechanics, field technicians, and users of small engines or pneumatic devices will appreciate the material and temperature tolerance.

It is less suitable for applications exposed to low molecular organic acids, ammonia gas, strong alkalis, amines, glycol-based brake fluids, or super-heated steam; installers working with those substances should seek a different elastomer specifically rated for those chemistries.

Pros & Cons

Pros

• Excellent chemical and heat resistance from Viton, so it holds up well in high-temperature and fuel-exposed environments.
• Customers report good fit and leak resistance for common replacements like fuel bottle seals and barrel seals.
• Durable 75A hardness that balances resilience and sealing ability, offering strong value for money.

Cons

• Not compatible with certain chemicals such as low molecular organic acids, ammonia, alkalis, and glycol-based brake fluids, limiting use in those specific systems.

Specifications

Material	Viton (fluorocarbon elastomer)
Color	Black
Dimensions	9 in ID, 9-1/2 in OD, 1/4 in width
Durometer	75A (shore)
Temperature range	-15 degrees F (-26 degrees C) to 400 degrees F (205 degrees C)
Cross-section	Round
Standards	Meets AS568A sizing

Our Verdict

The 447 Viton O-ring is a practical, cost-effective choice when you need a heat- and fuel-resistant seal for cylindrical fittings. It is especially good for replacements in fuel-handling and heated environments where Viton compatibility is required, and offers solid durability and leak resistance for the price; avoid it only when your system uses chemistries incompatible with fluorocarbon elastomers.

Frequently Asked Questions

Will this O-ring handle gasoline and diesel?
Yes, it is compatible with many fuels and aromatic and aliphatic hydrocarbons, making it suitable for gasoline and diesel exposure.

Can I use this in high vacuum systems?
Yes, Viton is commonly used in high vacuum environments and performs well when outgassing and permeability meet the application requirements.

Is this safe for brake fluid and ammonia environments?
No, Viton is vulnerable to glycol-based brake fluids, ammonia, and some alkalis, so choose a different material for those fluids.