III. Feature Description

A. Single-Seat Design: Precision Flow Regulation

• High Throttling Accuracy: The plug-seat assembly forms a narrow flow passage that responds linearly to actuator movement, enabling flow rate adjustments within ±1% of setpoint. In a chemical reactor feed line, this precision ensures consistent reactant dosing, improving product quality and yield.
• Minimized Cavitation & Noise: The streamlined flow path and optional anti-cavitation trim reduce pressure drop gradients, preventing vapor bubble formation (cavitation) that damages valve internals. In a power plant’s steam turbine bypass line, this feature eliminated valve noise and extended trim life by 5 years.
• Leak-Tight Shut-Off: The precision-ground plug and seat (Ra ≤0.2μm) deliver ANSI/FCI Class IV (hard seal) or Class VI (soft seal) leakage performance. For a pharmaceutical plant’s sterile process line, the soft-seal option prevented product contamination via near-zero leakage.

B. Pneumatic Actuation: Speed & Automation Compatibility

• Rapid Response: Double-acting pneumatic actuators adjust valve position in 0.5–2 seconds, enabling real-time correction of process deviations (e.g., pressure spikes in oil refinery lines). This speed outperforms electric actuators in fast-paced processes.
• Fail-Safe Operation: Spring-return actuators provide critical safety in hazardous applications—auto-closing (or auto-opening) the valve if air supply fails. In a natural gas processing plant, this feature prevented uncontrolled gas release during a compressor outage.
• DCS/SCADA Integration: 4–20mA positioners translate control signals into precise valve movements, integrating seamlessly with industrial automation systems. For a water treatment plant with 50+ valves, this centralized control reduced operator intervention by 70% and improved process efficiency.

C. Material Versatility: Adaptability to Harsh Media

• A105 Carbon Steel: Ideal for non-corrosive media (steam, oil, treated water) in power plants and refineries. Its high tensile strength withstands PN150 pressure without deformation, while cost-effectiveness makes it suitable for large-scale projects.
• 316 Stainless Steel: Resists chlorides, acids, and alkalis—perfect for coastal water treatment plants, chemical processing lines, and marine applications. In a seawater desalination facility, 316 stainless steel valves maintained integrity for 8 years, outperforming carbon steel alternatives.
• Stellite 6/Ceramic Trim: For abrasive media (e.g., mining slurries, catalyst-laden gas), hard-faced or ceramic trim resists wear and erosion. In a cement plant’s raw material handling line, ceramic trim valves operated reliably for 6 years, compared to 1 year for standard steel trim.

D. Globe-Style Body: Turbulence Reduction & Efficiency

• Low Turbulence Flow: The Z-shaped flow path redirects fluid through the plug-seat assembly, reducing turbulence and improving flow stability. This results in more accurate flow measurement and control, critical for processes requiring consistent pressure (e.g., pharmaceutical blending).
• Energy Efficiency: The streamlined flow path minimizes pressure drop (Cv values up to 500 for DN300), reducing pump energy consumption by 15–20% compared to butterfly valves. For a municipal water utility, this translated to annual energy savings of $25,000 across 100 valves.
• Easy Maintenance: The bolted bonnet design allows quick access to internal components (plug, seat, stem) without removing the valve from the pipeline. In a chemical plant, valve servicing time was reduced from 4 hours to 1 hour, minimizing downtime.

E. Fire-Safe & Anti-Static Features: Safety in Hazardous Environments

• Fire-Safe Compliance: API 607 certification ensures metal-to-metal sealing if non-metallic seals burn in a fire. In a petrochemical refinery, this prevented catastrophic fuel leakage during a pipeline fire, limiting environmental damage.
• Anti-Static Protection: A conductive path between the plug, stem, and body dissipates static charges (resistance ≤10Ω), eliminating spark risks in flammable media (e.g., gasoline, propane). This feature aligns with ATEX/IECEx standards for hazardous area use.

IV. Manufacturing Processes

A. Material Inspection & Preparation

• Material Verification: A105/316 stainless steel billets are tested via spectral analysis to confirm chemical composition (e.g., Cr: 16–18% for 316, C: 0.25–0.35% for A105) and ultrasonic testing (UT) to detect internal defects. Mechanical testing (tensile strength, impact resistance) ensures compliance with ASTM standards, documented in Material Test Reports (MTRs).
• Heat Treatment: A105 billets undergo normalizing (900–950℃, air-cooled) to relieve forging stresses; 316 stainless steel undergoes solution annealing (1010–1120℃, water-quenched) to restore corrosion resistance.
• Trim Material Validation: Stellite 6 is tested for hardness (≥58 HRC) and chemical composition; ceramic trim undergoes fracture toughness testing to ensure durability in abrasive media.

B. Valve Body & Trim Fabrication

• Body Manufacturing: A105/316 bodies are produced via forging (PN100-PN150) or precision casting (PN25-PN64) to ensure structural integrity. Forged bodies eliminate internal porosity, critical for ultra-high-pressure service; cast bodies offer cost-effectiveness for medium-pressure applications.
• CNC Machining: Critical surfaces—flange faces, bonnet bores, and seat pockets—are machined using 5-axis CNC centers. Flange faces meet ASME B16.5 flatness (≤0.05mm/m) and surface finish (Ra ≤3.2μm); seat pockets are machined to ±0.02mm tolerance for precise plug-seat alignment.
• Trim Fabrication: Valve plugs and seats are precision-ground using cylindrical grinders to achieve Ra ≤0.2μm surface finish. Stellite 6 hardfacing is applied via plasma transfer arc (PTA) welding, then ground to match the seat’s profile. Anti-cavitation trim features multi-stage pressure reduction grooves, machined via EDM (Electrical Discharge Machining) for precision.

C. Actuator Integration & Assembly

• Stem & Packing Installation: The valve stem is inserted into the bonnet, with graphite-impregnated PTFE packing installed in layers to balance sealing and torque. Packing compression is controlled (10–15%) to minimize fugitive emissions (ISO 15848-1 Class BH).
• Actuator Mounting: Pneumatic 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.
• Manual Override Assembly: Worm gear or lever overrides are integrated into the actuator, tested to ensure smooth operation without interfering with pneumatic/electric control.

D. Quality Testing & Certification

• Hydrostatic Testing: Per API 598, the valve shell is tested at 1.5× rated pressure (e.g., 22.5MPa for PN150) 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.
• Operational Testing: The valve is cycled 500 times (open/close) to verify actuator response time, position accuracy, and seal integrity. Pneumatic models are tested for air tightness (0.6MPa) to ensure no actuator leakage.
• Non-Destructive Testing (NDT): Welds (e.g., Stellite 6 trim welds) 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 600, ISO 9001). For hazardous area applications, ATEX/IECEx certificates are provided.