III. Feature Description

A. Midline (Concentric) Design: Uniform Sealing & Low Torque

• Uniform Seat Wear: Even contact pressure across the sealing surface eliminates uneven wear, extending seal life by 2-3 times in cyclic operations (e.g., municipal water distribution).
• Low Operational Torque: Concentric alignment reduces friction, requiring only 80-100 N·m of torque for a DN175 worm gear model—enabling manual operation without specialized tools.
• Full-Bore Flow: When fully open, the disc is parallel to the flow, minimizing pressure drop and reducing pumping energy costs by 15-20% compared to restrictive valves.

B. Material Synergy: Corrosion Resistance & Durability

• Ductile Iron Body: DI’s ductility absorbs shock and vibration, making it ideal for municipal pipelines subject to ground movement. In buried water mains, DI valves withstand soil settlement without cracking, unlike brittle cast iron alternatives.
• Aluminum Bronze Disc: The alloy’s corrosion resistance in water is unmatched, making it suitable for seawater or brackish applications (e.g., coastal sewage treatment). In marine outfall systems, it operates reliably for 10 years, while carbon steel discs corrode within 3 years.
• Rubber Soft Seal: EPDM/NBR lining provides elastic sealing that compensates for misalignments or surface imperfections. In potable water systems, EPDM’s FDA compliance ensures no contamination, and its resilience extends service life in systems with occasional particulates.

C. Lug-Type Connection: Installation Flexibility

• Versatile Mounting: Installation with through-bolts or stud bolts simplifies retrofitting older pipelines, where matching flange bolt patterns is challenging.
• Easy Maintenance: Valves can be removed for maintenance without disturbing adjacent pipeline flanges, reducing downtime in water treatment plants.
• Space Optimization: Lug valves require less axial space than wafer or flanged valves, making them ideal for cramped urban piping vaults.

D. Soft Seal Performance: Leak-Tight Reliability

• Bubble-Tight Sealing: ANSI/FCI Class VI performance ensures ≤0.1×DN mm³/min leakage for water—critical for potable water and sewage systems to prevent contamination or environmental discharge.
• Thermal & Chemical Compatibility: EPDM resists oxidation, ozone, and most water-based chemicals (pH 5-9), while NBR suits oil-resistant industrial wastewater.
• Resilience to Minor Damage: The rubber seal’s elasticity recovers from minor abrasions, extending service life in systems with occasional particulate matter (e.g., sand in well water).

IV. Manufacturing Processes

A. Material Inspection & Preparation

• DI Verification: Spectral analysis confirms chemical composition, and ultrasonic testing detects internal defects. Mechanical testing ensures compliance with ASTM A536.
• Aluminum Bronze Validation: Disc blanks are tested for chemical composition and hardness to ensure corrosion and wear resistance.
• Rubber Lining Checks: EPDM/NBR rubber is tested for hardness, tensile strength, and elongation to ensure sealing integrity.

B. Valve Body & Disc Fabrication

• Body Manufacturing: DI bodies are sand-cast, shot-blasted, and CNC-machined to meet AWWA C504 flatness and surface finish standards.
• Disc Fabrication: Aluminum bronze discs are precision-turned and milled for concentricity with the stem, with a sharp yet durable edge profile.
• Rubber Lining Application: The body’s seat area is grit-blasted, then EPDM/NBR rubber is bonded via heat and pressure for uniform thickness and adhesion.

C. Assembly & Quality Testing

• Stem & Disc Assembly: The stainless steel stem is keyed to the disc, tested for concentricity (runout ≤0.1mm).
• Hydrostatic Testing: Per API 598, the body is tested at 1.5× PN10, and the seat at 1.1× PN10, with no leakage allowed.
• Operational Testing: The valve is cycled 100 times to verify smooth operation, torque, and seal integrity.

D. Final Inspection & Documentation

• Visual Inspection: Checks for surface defects, proper marking, and compliance with AWWA C504.
• Documentation: Includes MTRs, hydrostatic test reports, and compliance certificates (API 609, ISO 9001, WRAS/NSF 61 optional).