III. Feature Description

A. Wafer Type Structure: Compact & Space-Saving

• Space Optimization: The valve’s slim profile (face-to-face length as short as 100mm for DN100) eliminates the need for bulky flanged valve bodies, making it ideal for crowded piping racks in power plants, cement kilns, and chemical facilities. In a DN1000 pipeline, the wafer valve reduces installation space by 50% compared to flanged butterfly valves.
• Easy Installation: The valve is sandwiched between two pipeline flanges and secured with bolts, eliminating the need for dedicated valve flanges. This reduces installation time by 40% and lowers hardware costs (fewer bolts, gaskets required). For a cement plant’s DN1500 flue gas pipeline, installing 10 wafer valves saved 3 days of shutdown time compared to flanged alternatives.
• Lightweight Design: Stainless steel wafer construction is 30–40% lighter than flanged valves of the same size, reducing structural load on pipelines and simplifying handling during installation.

B. Metal Hard Seal: High-Temperature Resilience

• High-Temperature Compatibility: The stainless steel/Stellite 6 seal retains integrity up to 420℃, making the valve suitable for hot media such as flue gas (cement kilns), steam (power plants), and molten salt (solar thermal systems). Soft-sealed valves would degrade rapidly in these environments, requiring frequent replacement.
• Wear & Corrosion Resistance: The hard-seal surface resists abrasion from particulate-laden media (e.g., dust in cement pipelines, scale in power plant steam lines) and corrosion from industrial chemicals (e.g., acidic byproducts in metallurgy). In a steel mill’s blast furnace cooling system, the valve operated reliably for 8 years, while soft-sealed valves failed within 18 months.
• Leak-Tight Performance: The precision-machined disc and seat (Ra ≤0.2μm) deliver ANSI/FCI Class IV leakage performance, preventing fugitive emissions of high-temperature media. This compliance with environmental regulations avoids costly fines and reduces safety risks in industrial settings.

C. Pneumatic Actuation & Positioner: Precision Flow Control

• Precise Throttling: The 4–20mA positioner converts control signals into linear valve movement, enabling flow rate adjustments within ±1% of setpoint. In a chemical plant’s reactor feed line, this precision ensures consistent media dosing, improving product quality and yield.
• Rapid Response: Double-acting pneumatic actuators adjust valve position in 1–3 seconds, enabling real-time correction of process deviations (e.g., pressure spikes in power plant boiler feedwater lines). This speed outperforms electric actuators in fast-paced industrial processes.
• Fail-Safe Operation: Spring-return pneumatic actuators provide critical safety in hazardous applications—auto-closing (or auto-opening) the valve if air supply fails. In a cement plant’s kiln flue gas pipeline, this feature prevented uncontrolled emissions during a compressor outage.

D. Multi-Drive Adaptability: Flexibility for Diverse Operations

• Pneumatic Actuation: Ideal for continuous-process industries (metallurgy, chemical) where compressed air is readily available, offering low energy consumption and reliable performance.
• Electric Actuation: Suited for remote or large-diameter applications (DN1000+), enabling centralized control via SCADA/DCS systems. The IP67-rated actuator withstands harsh industrial environments (dust, moisture, temperature fluctuations).
• Manual Operation: Handle/handwheel options provide backup control for small-scale or low-frequency use (e.g., maintenance bypass lines), ensuring operational continuity during power/air outages.

E. Stainless Steel Construction: Durability & Corrosion Resistance

• Corrosion Resistance: 304 stainless steel resists rust and mild corrosion from water, steam, and industrial chemicals—ideal for power plant cooling systems and chemical process lines. 316 stainless steel adds molybdenum for enhanced resistance to chlorides (e.g., coastal power plants, seawater cooling systems).
• Thermal Stability: Stainless steel retains its mechanical properties up to 420℃, avoiding deformation or fatigue in high-temperature applications. In a metallurgical plant’s hot gas pipeline (380℃), the valve maintained structural integrity for 10 years.
• Hygienic & Easy to Clean: The smooth, non-porous surface of stainless steel prevents media adhesion and bacterial growth, making it suitable for food-grade or pharmaceutical applications (with optional electropolishing).

IV. Manufacturing Processes

A. Material Inspection & Preparation

• Stainless Steel Verification: 304/316 stainless steel billets are tested via spectral analysis to confirm chemical composition (Cr: 18–20% for 304, Cr: 16–18%, Mo: 2–3% for 316) and ultrasonic testing (UT) to detect internal defects (porosity, cracks). Mechanical testing (tensile strength, impact resistance) ensures compliance with ASTM A240 standards, documented in Material Test Reports (MTRs).
• Heat Treatment: Stainless steel components undergo solution annealing (1010–1120℃, water-quenched) to relieve internal stresses from manufacturing and restore corrosion resistance—critical for high-temperature service.
• Seal Material Validation: Metal seal components (stainless steel/Stellite 6) are tested for hardness (≥58 HRC for Stellite 6) and thermal stability (up to 420℃) to ensure wear resistance in extreme conditions.

B. Valve Body & Disc Fabrication

• Body Manufacturing: Stainless steel valve bodies are produced via precision casting (DN100-DN500) or forging (DN600-DN2000) to ensure structural integrity. Cast bodies undergo shot blasting to remove scale and surface impurities; forged bodies are normalized to enhance ductility.
• CNC Machining: Critical surfaces—flange contact faces, valve seat pockets, and stem bores—are machined using 5-axis CNC centers. Flange contact faces meet ASME B16.24 flatness (≤0.05mm/m) and surface finish (Ra ≤3.2μm) for proper gasket seating. The valve seat pocket is machined to ±0.02mm tolerance for precise disc-seat alignment.
• Disc Fabrication: Butterfly discs are precision-turned and milled to achieve a uniform thickness and offset profile. The disc edge is ground to Ra ≤0.2μm for tight sealing contact, with optional Stellite 6 hardfacing applied via plasma transfer arc (PTA) welding for abrasive media.

C. Seal & Actuator Integration

• Seal Installation: Metal valve seats are press-fitted into the body pocket, with spring loading to compensate for thermal expansion. The seat-disc interface is lapped to achieve ANSI/FCI Class IV leakage performance.
• Stem & Packing Installation: The valve stem is inserted into the body, with graphite-impregnated PTFE packing installed in layers to balance sealing and operational torque. Packing compression is controlled (10–15%) to minimize fugitive emissions and stem friction.
• Actuator Mounting: Pneumatic/electric actuators are mounted via ISO 5211 adapter flanges, with laser alignment to ensure coaxiality (stem runout ≤0.05mm). Positioners are calibrated to convert 4–20mA signals into linear valve movement, with accuracy within ±0.5% of full stroke.

D. Quality Testing & Certification

• Hydrostatic Testing: Per API 598, the valve shell is tested at 1.5× rated pressure (0.15MPa for PN1) for 30 minutes—no leakage, sweating, or deformation is allowed. Seat testing is performed at 1.1× rated pressure, with leakage measured via bubble counting (≤1 bubble per minute for Class IV).
• Flow Capacity (Cv) Testing: Per ISO 6283, the valve is tested in a flow loop to verify Cv values, ensuring compliance with design specifications. This testing confirms throttling accuracy and flow control performance.
• High-Temperature Testing: Valves are subjected to thermal cycling (ambient to 420℃) to verify seal integrity and structural stability under extreme temperature fluctuations.
• Non-Destructive Testing (NDT): Welds (e.g., Stellite 6 hardfacing) undergo liquid penetrant testing (PT); forged bodies are inspected via magnetic particle testing (MPI) to detect surface defects.

E. Final Inspection & Documentation

• Visual Inspection: The valve is checked for surface defects (scratches, dents), proper marking (size, pressure rating, material, serial number), and compliance with ASME B16.34. Marking is permanent (laser-etched) for traceability.
• Documentation: Each valve includes MTRs for all materials, hydrostatic/flow test reports, actuator calibration certificates, and compliance documents (API 609, ISO 9001). For hazardous area applications, ATEX/IECEx certificates are available upon request.