The key differences between ‌concentric‌ and ‌triple eccentric butterfly valves‌ are as follows:

1. ‌Stem and Disc Alignment‌

   • ‌Concentric‌: The valve stem, disc, and body centers are aligned in the same position. This design is simple and cost-effective, commonly used in rubber-lined valves‌.
   • ‌Triple eccentric‌: The stem is offset three times (eccentricity in shaft, disc, and seat planes), reducing friction and wear, making it suitable for high-pressure and high-temperature applications‌.

2. ‌Sealing Mechanism‌

   • ‌Concentric‌: Relies on soft seating (e.g., rubber) for tight closure, prone to wear over time‌.
   • ‌Triple eccentric‌: Uses a metal-to-metal seal with wedging action, ensuring long-term durability and zero leakage‌.

3. ‌Performance‌

   • ‌Concentric‌: Best for low-pressure, moderate-temperature systems (e.g., water treatment)‌.
   • ‌Triple eccentric‌: Ideal for demanding conditions like steam, oil, and corrosive media due to its superior sealing and torque efficiency‌.

4. ‌Application Scope‌

   • ‌Concentric‌: Limited to throttling and basic isolation tasks‌.

   • ‌Triple eccentric‌: Used in critical processes requiring tight sealing and minimal maintenance‌.