II. Key Attribute Parameters

• Size Range: DN15~DN600 (1/2″~24″), covering small to large-diameter pipelines for diverse applications from residential water lines to industrial main pipelines.
• Pressure Rating: PN16 (Class 150), suitable for low to medium pressure systems such as water distribution networks and steam auxiliary pipelines.
• Temperature Range: Varies by material:
  • WCB/CF8M: -29℃~425℃
  • WC6: -29℃~550℃
  • LCB: -46℃~350℃
• Material Configuration:
  • Body & Bonnet: Ductile iron (for water supply), WCB (carbon steel, general industrial), CF8M (stainless steel, corrosive media).
  • Wedge: Elastic wedge (flexible design) matching body material, ensuring tight sealing even with pipeline misalignment.
  • Stem: F6a (carbon steel), F316 (stainless steel for corrosion resistance), with rising stem design for clear position indication.
  • Seal: Resilient seated (rubber/PTFE) + flexible graphite packing, achieving tight shut-off and resisting media erosion.
  • Bolt & Gasket: A193-B7 bolts (high strength), 18-8 stainless steel with graphite gasket (leak-tight under pressure).
• Connection Type: Flange (per ANSI B16.5, DIN, BS), enabling secure integration with pipeline flanges and easy installation.
• Operation: Manual (handwheel) with optional gear operator for large-diameter valves (DN300+), reducing operating torque.

III. Features Description

• Resilient Seated Elastic Wedge: The flexible wedge adapts to minor pipeline misalignment or thermal expansion, ensuring consistent contact with the valve seat. The resilient seal (rubber/PTFE) enhances shut-off performance, achieving ANSI/FCI Class IV leakage—critical for preventing water loss in municipal supply systems.
• Outside Screw & Yoke (OS&Y) Structure: The stem is exposed outside the bonnet, with threads isolated from media. This design avoids stem corrosion by media, extends service life, and provides visual confirmation of valve position (open/closed) via stem extension—essential for safety in industrial pipelines.
• Full-Port Design: The flow path diameter matches the pipeline, minimizing pressure drop and energy loss. This is particularly beneficial for water supply systems, where efficient flow reduces pumping costs.
• Bolted Bonnet: Securely fastened with bolts, the bonnet allows easy access to internal components (wedge, packing) for maintenance. This modular design simplifies replacement of worn parts without removing the valve from the pipeline.
• Material Versatility: Ductile iron for cost-effective water supply; WCB for high-temperature steam; CF8M for corrosive media like nitric acid. This range eliminates the need for multiple valve types in complex systems.

IV. Manufacturing Processes

• Material Validation: Ductile iron/WCB/CF8M castings undergo ultrasonic testing to detect internal defects. Chemical analysis verifies alloy composition (e.g., CF8M’s Cr16-18%, Mo2-3%) to ensure corrosion resistance.
• Wedge & Seat Machining: The elastic wedge is precision-machined to ensure flexibility within 0.5mm tolerance, allowing adaptation to pipeline changes. Seat surfaces are ground to Ra ≤1.6μm, then bonded with resilient seals (rubber/PTFE) via high-temperature adhesive.
• Stem & Bonnet Assembly: The stem is threaded with precision (ISO metric threads) to ensure smooth rising/descending. The bonnet is bolted to the body with uniform torque (50-80N·m) to avoid leakage, and packing (flexible graphite) is layered to prevent stem leakage.
• Testing:
  • Hydrostatic Test: Body tested at 1.5×PN16 (2.4MPa) for 30 minutes; seat tested at 1.1×PN16 (1.76MPa) with water to confirm no leakage.
  • Operation Test: Manual/gear operation tested for 100+ cycles to ensure smooth stem movement and no jamming.
  • Material Performance Test: High-temperature (550℃ for WC6) and low-temperature (-46℃ for LCB) tests verify material toughness under extreme conditions.