Triple Offset Metal Seated Butterfly Valve – YONCO Hard Seal Series
The YONCO Triple Offset Metal Seated Butterfly Valve (D343H / D343W Series) is engineered to handle the most demanding industrial environments. Utilizing an advanced triple eccentric design, this valve achieves zero-friction operation, eliminating wear between the disc and the valve seat. It provides bubble-tight, bi-directional sealing performance in severe conditions, including high temperatures, cryogenic applications, and highly corrosive media.
Core Features & Advantages
- Triple Offset Design: Eliminates rubbing and friction during the 90-degree rotation, ensuring a longer service life and decreasing operating torque. Features a “tighter as it closes” dynamic sealing function.
- Laminated Metal Seal: The sealing ring is composed of stainless steel and flexible graphite (or PTFE). It combines the robustness of a metal hard seal with the zero-leakage capability of an elastic seal, excelling in both high and low temperatures.
- Stellite Overlay Seat: The disc sealing face is hard-faced with Cobalt-based alloy (Stellite / 507), providing outstanding resistance to wear, erosion, and corrosion.
- Large-Diameter Truss Structure: For large sizes (up to DN4000), the disc features a high-strength truss structure. This maximizes the flow area and significantly reduces fluid resistance.
- Bi-Directional Sealing: Customizable for bi-directional sealing upon request, allowing installation in any direction regardless of the media flow or spatial constraints.
- Flexible Actuation: The top flange allows actuators to be mounted in multiple positions (90° or 180° rotation) for user convenience.
Performance & Specifications
| Specification Parameter | Details |
|---|---|
| Nominal Diameter (DN) | DN50 – DN4000 (2″ – 160″) |
| Nominal Pressure (PN) | PN10, PN16, PN25 (1.0 MPa – 2.5 MPa) |
| Applicable Temperature | ≤ 425°C (Graphite Seal) / ≤ 200°C (PTFE Seal) |
| Body & Disc Material | WCB (Carbon Steel), CF8 (SS304), CF3M (SS316L) |
| Stem Material | 2Cr13, SS304, SS316L |
| Applicable Media | Water, Steam, Oil, Coal Gas, Combustible Gas, Nitric/Acetic Acid |
Main Application Fields
• Power Generation Plants
• Metallurgical Industry
• Petrochemical & Refining
• Municipal Water & Wastewater
• Gas Pipeline Networks
• Chemical Processing (Corrosive Media)
YONCO Valve Engineering Excellence
YONCO sets the standard for high-performance fluid control. Our triple offset butterfly valves undergo rigorous pressure and leakage testing (GB/T 13927 / API 598 equivalents) to ensure absolute safety and reliability in critical pipeline isolation. Available in flanged, wafer, and lug types to meet your specific project requirements.




