Choosing the right butterfly valve often boils down to the seal type. Understanding the key differences between hard-seal and soft-seal valves is crucial for performance and longevity. Here's a quick breakdown:

Soft-Seal Butterfly Valves:

• Seal: Uses an elastomer (like EPDM, NBR, Viton) or polymer (like PTFE) seat bonded or pressed onto the disc or body.

• Pros: Excellent, bubble-tight shut-off (Zero Leakage). Lower operating torque. Generally lower initial cost. Good for slurries.

• Cons: Limited temperature range (degrades over time with heat/cold). Vulnerable to wear, abrasion, and chemical attack. Shorter lifespan under harsh conditions.

• Best For: Water, air, moderate temperatures, non-abrasive fluids where zero leakage is critical.

  
  

• Hard-Seal Butterfly Valves:

• Seal: Uses metal-to-metal (or metal with hard coatings like Stellite, nickel alloy) sealing surfaces between the disc and body seat.

• Pros: Handles very high temperatures and pressures. Resists abrasion, erosion, and chemical corrosion much better. Longer service life in demanding applications.

• Cons: Generally higher initial cost. Slightly higher operating torque. Achieving absolute zero leakage can be harder initially than soft seals (though very low leakage is standard).

• Best For: High temps, high pressures, abrasive/corrosive fluids (steam, chemicals, dry powders), frequent cycling, demanding industrial processes.
  

  
  

• Conclusion
  Need a tight, affordable seal for moderate conditions? Soft-seal is likely your choice. Facing high heat, pressure, abrasion, or harsh chemicals? Hard-seal is the robust, long-term solution. Always match the valve to your specific fluid, pressure, temperature, and duty cycle!
  

  
  

• QINGDAO FLUIDO offer soft-sealed butterfly valves. If you have any needs, please free to contact us. We guarantee the product quality and provide you with the best products.