Viton (FKM) vs. EPDM Valve Seats for Butterfly Valves: Choosing the Best Material for Pneumatic Unloaders in Bulk Handling Operations

In bulk handling industries like cement, bentonite, barite, fly ash, and other powder-based materials, pneumatic unloaders and butterfly valves play a crucial role in controlling and directing the flow of materials. The choice of valve seat material can significantly impact valve performance, durability, and maintenance. Two of the most commonly used materials for valve seats in butterfly valves are Viton (FKM) and EPDM. This blog will explore the differences between these materials, how they perform in bulk handling systems, and how to make the best choice for your specific needs.

Understanding Viton (FKM) Valve Seats:

Viton (FKM) is a type of fluorocarbon elastomer, widely known for its exceptional chemical resistance and high-temperature stability. In bulk material handling, where valves often deal with aggressive chemicals or hot air used in unloading processes, Viton valve seats provide several key advantages:

1. Superior Chemical Resistance: Viton is highly resistant to a wide range of chemicals, oils, and fuels. It excels in handling aggressive substances commonly found in industrial applications, such as cement and bentonite.
2. High-Temperature Performance: Viton can withstand high temperatures (up to 200°C or 392°F), making it ideal for applications with high operating temperatures. This is particularly beneficial when dealing with the hot compressed air used in pneumatic unloaders.
3. Excellent Sealing: Viton valve seats offer superior sealing capabilities, minimizing leakage and ensuring efficient material handling without contamination.

However, Viton does come with some trade-offs:

• Higher Cost: Viton materials tend to be more expensive than EPDM, impacting the overall cost of valve systems.
• Limited Flexibility at Low Temperatures: Viton can lose flexibility at temperatures below -15°C (5°F), which could affect its performance in cold storage applications or regions with extreme climates.

Understanding EPDM Valve Seats:

EPDM (Ethylene Propylene Diene Monomer) is a synthetic rubber that is particularly effective for handling water, steam, and weathering conditions. It’s commonly used in systems that require resistance to environmental elements but may face limitations in chemical handling.

1. Water and Weather Resistance: EPDM’s resistance to water, steam, and UV exposure makes it an ideal choice for outdoor and marine environments. For bulk handling in ports or cement storage, EPDM performs well in humid or wet conditions.
2. Cost-Effective: EPDM is generally a more budget-friendly option compared to Viton, making it an attractive choice for cost-conscious operations.
3. Wide Temperature Flexibility: EPDM maintains flexibility across a broad temperature range (-40°C to 150°C or -40°F to 302°F), making it suitable for a variety of environmental conditions.

However, EPDM may not be the best option for all pneumatic unloading systems:

• Limited Chemical Resistance: EPDM is not as resistant to aggressive chemicals, oils, and fuels compared to Viton, which can make it less suitable for harsh industrial environments.
• Lower Temperature Resistance: While EPDM performs well at lower temperatures, prolonged exposure to high temperatures can degrade its performance.

How to Choose the Right Valve Seat Material for Your Butterfly Valve:

When selecting the appropriate valve seat material for pneumatic unloaders in bulk handling operations, consider these key factors:

1. Fluid and Chemical Compatibility: Evaluate the types of materials your valves will be in contact with, such as cement, fly ash, or barite. Choose a material that can withstand both chemical exposure and the particulate nature of these materials.
2. Temperature Range: Determine the operating temperature of your pneumatic unloading system. If you deal with heated air or harsh climates, Viton’s high-temperature stability will be beneficial.
3. Cost Considerations: Balance your performance needs with your budget. EPDM is a more cost-effective option, but if chemical resistance and high-temperature durability are crucial, Viton may be worth the extra investment.
4. Environmental Factors: If your operation is exposed to weathering, UV radiation, or outdoor conditions, EPDM may be more suitable, while Viton is better for indoor environments with more controlled conditions.

Conclusion:

Choosing the right valve seat for your butterfly valve is crucial for ensuring long-term durability and efficient operation in pneumatic unloaders and other bulk handling systems. Viton (FKM) is ideal for high-temperature and chemical-resistant applications, while EPDM offers excellent flexibility and cost-effectiveness for water and weather-resistant needs. Consider your operation's specific requirements to select the best material for your butterfly valve seats.

At www.Liontech.shop, we offer a range of butterfly valves with Viton and EPDM seats designed for optimal performance in various bulk handling applications. Browse our catalogue to find the perfect solution for your needs, or contact our expert team for tailored guidance.