In industrial environments where heat, pressure, and aggressive chemicals are part of everyday operations, standard sealing solutions often fall short. This is where custom Viton® seals play a critical role. Engineered for durability and precision, these seals are designed to meet exact application requirements while delivering reliable performance in some of the harshest conditions imaginable.

Understanding Viton®: The Material Behind the Seal

Viton® is a brand name for a family of fluoroelastomer (FKM) materials known for exceptional resistance to heat, chemicals, and environmental exposure. Unlike general-purpose elastomers, Viton® is specifically formulated to perform where other materials degrade, swell, or fail.

Key performance characteristics of Viton® include:

• High temperature resistance, typically up to 400°F (204°C)

• Outstanding chemical resistance to fuels, oils, solvents, and acids

• Low compression set, allowing seals to maintain their shape and sealing force over long periods

• Excellent resistance to ozone, UV radiation, and weathering

These properties make Viton® a preferred material for sealing applications in industries such as oil and gas, chemical processing, aerospace, automotive, and heavy manufacturing.

What Makes a Viton® Seal “Custom”?

While standard Viton® O-rings and gaskets are widely available, many applications require sealing solutions that fall outside catalog dimensions or performance limits. A custom Viton® seal is designed and manufactured to meet specific requirements that standard parts cannot accommodate.

Customization may include:

• Non-standard diameters, thicknesses, or cross-sections

• Unique geometries or complex molded shapes

• Tight dimensional tolerances

• Specific hardness (durometer) values

• Custom Viton® formulations for enhanced chemical or temperature resistance

Custom Viton® seals can be produced in a wide range of forms, including:

• O-rings

• Gaskets

• Lip seals

• Quad rings (X-rings)

• Molded rubber seals

• Extruded and cut-to-length profiles

This flexibility allows manufacturers to tailor sealing solutions precisely to equipment design and operating conditions.

Why Choose Custom Viton® Seals?

The decision to use a custom Viton® seal is often driven by performance demands and reliability concerns. In critical systems, seal failure can result in leaks, equipment damage, safety hazards, and costly downtime.

Custom Viton® seals are typically chosen when:

• Standard seals do not fit or perform adequately

• Operating temperatures exceed the limits of conventional elastomers

• Exposure to aggressive chemicals or fuels is constant

• Long service life and minimal maintenance are required

• Regulatory or quality standards must be met

By tailoring the seal to the application, manufacturers can significantly improve system reliability and reduce total lifecycle costs.

The Manufacturing Process of Custom Viton® Seals

Producing custom Viton® seals involves a carefully controlled manufacturing process designed to ensure consistency, performance, and dimensional accuracy. While the exact workflow varies depending on seal type and production volume, most custom Viton® seals follow the same core steps.

1. Material Compounding

The manufacturing process begins with material compounding. Viton® base polymer is blended with curing agents, fillers, processing aids, and performance-enhancing additives. These ingredients are carefully measured to achieve the desired physical properties, such as hardness, elasticity, and chemical resistance.

Compounding is typically performed using an internal mixer or two-roll mill to ensure uniform distribution of all components. The result is a homogeneous rubber compound ready for forming.

2. Forming the Seal

Once compounded, the Viton® material is shaped into its final form using one of several manufacturing methods. The choice of forming process depends on part complexity, tolerance requirements, and production volume.

Compression Molding

Compression molding involves placing a measured amount of rubber into a heated mold cavity, which is then closed and compressed. Heat and pressure cause the material to flow and take the shape of the mold.

• Commonly used for custom O-rings, gaskets, and simple molded seals

• Cost-effective for low to medium production volumes

• Suitable for thick or solid cross-sections

Transfer Molding

In transfer molding, heated rubber is forced from a chamber into a closed mold cavity. This method offers better material flow than compression molding and is ideal for moderately complex geometries.

• Provides improved surface finish

• Better control over part detail

• Often used for seals with intricate features

Injection Molding

Injection molding is used for high-volume production and tight-tolerance applications. The Viton® compound is heated and injected under pressure into a closed mold.

• Excellent repeatability and consistency

• Minimal material waste

• Ideal for complex shapes and large production runs

Extrusion

For continuous profiles, Viton® is extruded through a die to produce a uniform cross-section. The extruded material is then cut, spliced, or vulcanized into finished seals.

• Common for custom profiles and long sealing elements

• Can be bonded or joined to form closed-loop seals

3. Vulcanization (Curing)

After forming, the seal undergoes vulcanization, a curing process that cross-links the polymer chains within the Viton® material. This step is critical, as it determines the final mechanical strength, elasticity, and chemical resistance of the seal.

Curing is performed under controlled heat and pressure conditions, with precise timing to ensure optimal performance without over-curing or degradation.

4. Post-Curing for Enhanced Performance

Many custom Viton® seals require post-curing, which involves baking the parts in an oven for an extended period. Post-curing serves several important functions:

• Removes residual curing agents and byproducts

• Improves high-temperature resistance

• Enhances chemical compatibility

• Reduces compression set

Post-curing is especially important for seals used in fuel systems, aerospace applications, and chemical processing equipment.

5. Finishing Operations

Once curing is complete, seals may undergo a variety of finishing operations to meet final specifications:

• Deflashing using mechanical or cryogenic methods

• Trimming to precise dimensions

• Surface treatments or coatings

• Bonding to metal or plastic inserts, if required

These steps ensure the seal fits properly and performs reliably in its intended application.

6. Inspection and Quality Control

Quality control is a critical part of custom Viton® seal manufacturing. Each batch may be inspected for:

• Dimensional accuracy

• Durometer (hardness)

• Surface defects

• Compression set

• Tensile strength and elongation

For regulated industries, manufacturers may also provide material certifications, lot traceability, and compliance documentation.

Applications of Custom Viton® Seals

Thanks to their durability and versatility, custom Viton® seals are used across a wide range of industries, including:

• Oil and gas: valves, pumps, and drilling equipment

• Chemical processing: reactors, pipelines, and containment systems

• Aerospace and aviation: fuel systems and high-temperature components

• Automotive: fuel injection systems and emission controls

• Industrial machinery: hydraulic and pneumatic systems

In each case, the ability to customize the seal ensures optimal performance and long service life.

The Value of Custom Engineering

Custom Viton® seals represent more than just a component—they are a strategic investment in equipment reliability and operational efficiency. By tailoring material properties, dimensions, and manufacturing processes to the application, manufacturers can deliver sealing solutions that outperform standard alternatives.

For operations that cannot afford failure, custom Viton® seals provide the confidence that critical systems will remain sealed, protected, and productive even in the most demanding environments.

Conclusion

Custom Viton® seals combine advanced material science with precision manufacturing to meet the challenges of modern industrial applications. From material compounding and molding to curing and inspection, every step of the process is designed to deliver performance, consistency, and durability.

Whether used in extreme temperatures, aggressive chemical environments, or mission-critical equipment, custom Viton® seals offer a reliable solution when standard sealing products are not enough. By understanding how they are made and why they are used, organizations can make informed decisions that enhance system performance and reduce long-term costs.