The triple-eccentric butterfly valve achieves a structural breakthrough in traditional butterfly valves through three-dimensional geometric eccentricity design (three-dimensional offset of the valve stem axis, valve disc axis and valve body sealing surface axis), becoming a key technical solution in the field of industrial fluid control.
1. Core Technology Innovation
| Technical features | Function Implementation |
|---|---|
| first eccentric | The valve stem axis deviates from the center of the valve body channel, reducing the initial contact pressure between the butterfly plate and the valve seat |
| second eccentric | The disc rotation center deviates from the sealing surface center, forming a progressive disengagement motion trajectory. |
| third eccentric | The cone angle of the sealing surface deviates from the pipeline axis to achieve torque sealing (non-traditional elastic deformation sealing). |
2. Significant Advantages Comparison
Zero leakage sealing performance
The contact pressure of the sealing surface is positively correlated with the medium pressure. It can still reach the ANSI Class VI leakage standard under PN160 (CL900) working conditions, and the metal hard seal leakage rate is <0.001%.
Ultra-low friction loss
The optimization of the butterfly plate motion trajectory reduces the friction contact area by 80%, and the opening and closing torque is further reduced by 35-50% compared with the double eccentric butterfly valve. The power of the DN600 valve electric actuator can be reduced to 1.5kW level.
Adaptability to extreme working conditions
Temperature range: -196℃ (liquid nitrogen) to +650℃ (high temperature flue gas)
Media compatibility: fluids containing solid particles (particle size ≤6mm, concentration ≤30%), strong corrosion (pH 0.5-14), and high viscosity (≤3000cP)
Long-term maintenance-free
The wear rate of the metal hard seal pair is <0.005mm/year, and the service life under typical working conditions can reach 15-20 years (opening and closing >500,000 times).
3. Typical application scenarios
| Industrial field | Key application points | Technical indicators |
|---|---|---|
| Petrochemical industry | Regeneration flue gas regulation of catalytic cracking unit (temperature resistance 600℃ + particle erosion) | Sealing surface hardness ≥HRC60 |
| Nuclear power system | Main steam isolation valve (radiation resistance + zero leakage) | ASME NQA-1 certification |
| LNG storage and transportation | -162℃ ultra-low temperature liquefied natural gas pipeline cutoff | Material low temperature impact toughness ≥100J@-196℃ |
| Metallurgical industry | Blast furnace gas residual pressure power generation (TRT) system pressure control | Withstand pressure fluctuation ±1MPa/second |
4. Key points for selection and implementation
Optimization of structural configuration
High temperature working conditions: Inconel 625 valve seat + Stellite 6 hard alloy coating is preferred
Corrosive media: Hastelloy C276 valve body + PTFE wrapped valve stem
Drive system matching
Large diameter (DN≥800) requires hydraulic actuator with thrust ≥200kN
When pneumatic actuators are selected in explosion-proof areas, ATEX/IECEx certification must be met
Installation and inspection specifications
Flange parallelism deviation ≤0.1mm/100mm to avoid seal failure caused by eccentric load
More than 3,000 thermal cycle tests (-196℃↔650℃) are required before leaving the factory
This valve type uses the torque sealing mechanism brought by three eccentricities to maintain the compact structure of the butterfly valve while breaking through the technical bottleneck of traditional valves under harsh working conditions such as high temperature, high pressure, and corrosion. Its core value lies in reducing the comprehensive cost of the entire life cycle by more than 40%, and it is a key equipment for the upgrading of process industries.
