III. Feature Description

• Floating Ball Structure Advantage: The ball core is not fixed by a shaft but “floats” in the valve body. When the valve is closed, medium pressure pushes the ball against the downstream seat, realizing automatic tight sealing. This design ensures bidirectional sealing (can block flow from either direction) and reduces machining accuracy requirements for the ball, balancing performance and cost.
• Pneumatic Drive Efficiency: Pneumatic actuators convert air pressure into rotational torque, enabling 90° fast switching (0.5s for DN15, 5s for DN300). Compared to manual valves, they reduce labor costs and improve response speed, critical for automated production lines.
• Reliable Sealing System: PTFE seats with low friction coefficient ensure smooth ball rotation and tight sealing. For high-temperature or abrasive media, metal-to-metal hard seals (stellite surfacing on seats/ball) are optional, with temperature resistance up to 400℃.
• Compact & Maintenance-Friendly: Integral valve body and actuator design saves installation space. The bonnet uses a bolted structure, allowing easy disassembly to replace seats or stems without removing the entire valve from the pipeline—reducing maintenance downtime.
• Safety & Compatibility: Equipped with a positioner (optional) for precise flow control; limit switches for remote status monitoring. Flange dimensions comply with international standards, ensuring compatibility with imported or domestic pipeline systems.

IV. Manufacturing Process

• Material Preparation: Carbon steel ingots (WCB) undergo ultrasonic testing to eliminate internal defects. Forged or cast into valve body/bonnet blanks, then rough-machined to basic dimensions (tolerance ±0.1mm).
• Ball & Seat Machining: 304 stainless steel balls are precision ground (roundness ≤0.005mm) and polished to Ra0.8μm. PTFE seats are molded and machined to match the ball curvature, ensuring 100% contact.
• Valve Assembly: Stem is assembled with the ball via a key connection; bonnet is bolted to the body with a graphite gasket for static sealing. Actuator is connected to the valve stem through a coupling, calibrated for 90° rotation accuracy (error ≤±1°).
• Sealing & Pressure Testing: Each valve undergoes two tests:
  • Shell Test: 1.5× nominal pressure (e.g., 6.0MPa for PN40) with water, holding 30 minutes to check for body/bonnet leakage.
  • Seat Test: 1.1× nominal pressure with air, using a bubble counter to verify zero leakage (≤1 bubble/min for Class150).
• Actuator Debugging: Pneumatic actuators are tested for action time, torque output, and spring return force (for spring-return models) to ensure consistency with design parameters.