I. Product Introduction
The Pneumatic Wafer Type Three-Eccentric Center Butterfly Valve is a high-performance industrial control valve that integrates a pneumatic actuator with a three-eccentric butterfly valve core. It adopts the “three-eccentric” structural design (eccentricity of valve shaft, eccentricity of sealing cone, and eccentricity of cone surface) to achieve zero-leakage hard sealing, while matching a pneumatic actuator for fast, automatic flow regulation.
This valve is widely used in pipelines for mediums such as water, steam, oil, gas, and weak corrosive chemicals in industries including petrochemicals, power generation, metallurgy, water treatment, and HVAC. Its wafer-type connection (clamped between pipeline flanges) saves installation space and simplifies disassembly, making it suitable for both on-off control and throttling applications requiring high sealing performance.
II. Product Features
- Three-Eccentric Hard Sealing: The three-eccentric structure ensures that the butterfly plate is fully separated from the valve seat during rotation, minimizing friction and wear. It achieves ANSI Class VI zero leakage (even for high-temperature/high-pressure media), with a longer service life (≥100,000 cycles).
- Pneumatic Fast Actuation: Equipped with a double-acting/single-acting pneumatic actuator, it completes opening/closing in 3–15 seconds (depending on size). The single-acting type has spring reset (fail-safe mode), ensuring system safety when air supply is interrupted.
- Wafer-Type Compact Design: The wafer connection eliminates the need for additional flange gaskets (integrated sealing), reducing pipeline weight and installation space. It is compatible with standard pipeline flanges (GB/ANSI/DIN), simplifying on-site assembly.
- High Temperature/Pressure Resistance: The valve body and butterfly plate use materials such as stainless steel (304/316) or alloy steel, paired with metal hard seals (or metal+PTFE composite seals), supporting medium temperatures up to 425℃ and pressures up to PN4.0 MPa.
- Low Flow Resistance: The streamlined butterfly plate design ensures a large flow area, with a flow coefficient (Cv) close to that of a fully open pipeline, reducing energy consumption of the system.
- Optional Manual Override: Equipped with a manual handwheel (as shown in the figure), it can be operated manually when the pneumatic system fails, ensuring continuous pipeline operation.
- Strong Adaptability: Supports accessories such as positioners, limit switches, and solenoid valves, enabling remote control and signal feedback. It is suitable for harsh working conditions (corrosive, high-temperature, high-pressure media).
III. Technical Data
| Technical Parameter | Specification |
|---|---|
| Valve Type | Pneumatic Wafer Type Three-Eccentric Center Butterfly Valve |
| Nominal Diameter (DN) | DN50 – DN600 (2″ – 24″) |
| Nominal Pressure (PN) | PN1.6, PN2.5, PN4.0 MPa; ANSI Class 150, 300 |
| Valve Body Material | Carbon Steel (WCB), Stainless Steel (304/316/316L), Alloy Steel (WC6/WC9) |
| Butterfly Plate Material | Stainless Steel (304/316/316L), Alloy Steel (1Cr13) |
| Sealing Type | Metal Hard Seal (PTC), Metal+PTFE Composite Seal |
| Sealing Grade | ANSI/FCI 70-2 Class VI (Zero Leakage) |
| Medium Temperature Range | -40℃ – 425℃ (varies with sealing material) |
| Medium Compatibility | Water, steam, oil, gas, weak acid/alkali, etc. |
| Actuator Type | Double-Acting / Single-Acting (Spring Return) |
| Actuator Air Pressure | 0.4 – 0.8 MPa (compressed air) |
| Opening/Closing Time | 3 – 15 seconds (DN50 – DN600) |
| Connection Standard | Wafer Type (GB/T 12224, ANSI B16.22, DIN EN 1092) |
| Actuator Protection Grade | IP65 (standard), IP67 (optional) |
| Optional Accessories | Pneumatic positioner, limit switch, solenoid valve, manual override handwheel |
| Service Life | ≥ 100,000 operating cycles |
四．The main shape and connection size
