III. Features Description

• Triple Eccentric Structure: The valve integrates three eccentric offsets to ensure the disc only contacts the seat at full closure—avoiding friction during opening/closing. This eliminates seal wear from media scouring, a common issue in concentric valves, and ensures the seal tightens under pressure for zero leakage.
• CF8 Corrosion Resistance: CF8 stainless steel (18% Cr, 8% Ni) forms a passive oxide layer, resisting rust and pitting from water, sediment, and mild chemicals. This outperforms carbon steel in humid or long-term water immersion environments, maintaining structural integrity for decades.
• Hard-Sealed Reliability: Stellite-coated disc (hardness ≥HRC55) and alloy seat form a metal-to-metal seal, withstanding sediment-laden water without seal damage. Unlike soft seals, it avoids aging or deformation, ensuring consistent performance in outdoor or unheated pipelines.
• Worm Gear Efficiency: The worm gear drive reduces operating torque by 60% compared to direct manual operation, allowing one person to easily control DN800 valves. Its self-locking function prevents accidental rotation from pipeline vibration, critical for large water networks.
• Large Flow Capacity: The rotary disc (90° rotation) creates minimal flow resistance when fully open, with a flow coefficient (Cv) 30% higher than gate valves of the same diameter—ideal for water transmission where energy efficiency is key.

IV. Manufacturing Processes

• Material Validation: CF8 stainless steel undergoes spectral analysis to verify alloy content and ultrasonic testing to detect internal defects. Stellite powder for sealing surfaces is inspected for purity to ensure wear resistance.
• Precision Machining: Body and disc are CNC-machined to tight tolerances (±0.05mm). The disc’s sealing surface is ground to Ra ≤1.6μm, then coated with Stellite via plasma welding to 0.5~1mm thickness, followed by precision grinding.
• Eccentric Calibration: The triple eccentric parameters are calibrated using 3D measurement to ensure the disc aligns with the seat only at full closure. Worm gear meshing is adjusted to 0.1~0.2mm clearance for smooth rotation.
• Assembly & Testing:
  • Components are assembled with torque-controlled fasteners, with the stem sealed via O-rings to prevent water ingress into the gearbox.
  • Hydrostatic Test: Body tested at 1.5×PN (2.4MPa for PN16) for 30 minutes; seat tested at 1.1×PN with water to confirm no leakage.
  • Operation Test: 50+ open/close cycles to verify worm gear smoothness and disc positioning accuracy.