III. Feature Description

A. A105 Forged Steel Construction: Strength & Durability

• Structural Integrity: Forging compacts the metal grain, eliminating porosity, shrinkage, and internal cracks common in cast valves. This dense grain structure enhances tensile strength and resistance to cyclic pressure loads—critical for high-pressure applications (e.g., oil & gas transmission) where valve failure could have catastrophic consequences.
• Thermal Stability: A105 carbon steel maintains its mechanical properties across a wide temperature range (-29℃ to 425℃), making it suitable for high-temperature steam service (e.g., power generation) and low-temperature process applications (e.g., natural gas processing).
• Cost-Effectiveness: A105 is a cost-effective alternative to stainless steel for non-corrosive or mildly corrosive media, reducing upfront costs while maintaining performance and durability.

B. 3PC Body Design: Maintenance Flexibility

• On-Line Maintenance: The valve’s split-body design (body, bonnet, end flanges) allows internal components (ball, seats, stem) to be inspected, repaired, or replaced without removing the valve from the pipeline. This reduces downtime by 60–70% compared to one-piece or two-piece valves—critical for continuous-process facilities like refineries or chemical plants.
• Modular Versatility: End flanges can be configured with different standards (ASME B16.5) or sealing surfaces (RF/RTJ) on the same valve, accommodating non-standard pipeline setups and reducing the need for custom adapters.
• Enhanced Sealing: The bonnet is bolted to the body with uniform torque, ensuring a tight seal between the body and bonnet—preventing leakage even under high pressure and thermal cycling.

C. Floating Ball Design: Reliable Sealing

• Self-Sealing Mechanism: The ball is not supported by trunnions; instead, media pressure pushes the ball against the outlet-side seat, creating a tight seal. This self-sealing design eliminates the need for complex trunnion supports, reducing valve weight and manufacturing cost while maintaining sealing integrity.
• Bidirectional Sealing: The floating ball design enables reliable sealing in both flow directions, eliminating the need for check valves and simplifying pipeline design. This is particularly valuable in systems where media flow may reverse (e.g., oil & gas gathering lines).
• Low Operational Torque: The PTFE/EPDM seat’s self-lubricating properties reduce friction between the ball and seat, lowering operational torque—enabling manual operation for medium-diameter valves (up to DN200 PN40) with a handwheel or worm gear.

D. Advanced Sealing Systems: Leak-Free Operation

• Self-Compensating Seats: Stainless steel springs preload the seat inserts, ensuring constant contact with the ball. As the seat wears over time, the spring automatically pushes the seat forward—compensating for wear and maintaining sealing force. This extends seat life by 50% compared to non-compensating designs.
• Versatile Seat Options: PTFE seats offer chemical inertness for non-oxidizing media (acids, solvents), EPDM seats excel with water and steam, and metal seats handle high temperatures and abrasive media—covering most industrial applications.
• Low Fugitive Emissions: Multi-layer graphite packing meets ISO 15848-1 Class AH standards, limiting methane leakage to ≤100ppmv—complying with EU Industrial Emissions Directive and US EPA regulations, reducing environmental impact and avoiding fines.

E. Flexible Actuation: Adaptable to System Requirements

• Manual Operation: Cost-effective for small-to-medium diameter valves (DN15-DN100) or systems with infrequent operation. The anti-slip handwheel provides clear visual confirmation of valve position (parallel to pipeline = open; perpendicular = closed).
• Pneumatic Actuation: Fast, reliable operation for automated systems (e.g., batch processing lines). Spring-return actuators provide fail-safe functionality (open or closed on air failure), enhancing safety in hazardous environments.
• Electric Actuation: Ideal for remote or precision control (e.g., SCADA-integrated oil & gas pipelines). Torque limiting and position feedback features prevent overloading and enable real-time monitoring of valve status.

IV. Manufacturing Process & Quality Control

A. Raw Material Procurement & Inspection

• Material Sourcing: A105 forged blanks, stainless steel components, and seal materials are sourced exclusively from ISO 9001-certified suppliers, with each batch accompanied by a Material Test Certificate (MTC) detailing chemical composition, mechanical properties, and heat treatment history.
• Material Verification: Incoming A105 blanks undergo spectral analysis (XRF) to confirm chemical compliance with ASTM A105 standards. Tensile, yield, and impact tests are performed on sample specimens—e.g., A105 must meet tensile strength ≥485MPa and impact toughness ≥27J at -20℃.
• Non-Destructive Testing (NDT): Forged components (body, bonnet, ball) undergo ultrasonic testing (UT) to detect internal defects and magnetic particle testing (MPI) to inspect surface flaws. Only defect-free materials proceed to machining.

B. Forging & Heat Treatment

• Precision Forging: A105 steel billets are heated in a controlled-atmosphere furnace to 1100–1250℃, then forged into body, bonnet, and ball shapes using hydraulic presses (500–2000 tons). The forging ratio is maintained at ≥3:1 to ensure dense grain structure and uniform mechanical properties.
• Heat Treatment:
  • A105 components: Normalizing (890–920℃, air-cooled) to relieve forging stress and refine grain structure. Post-heat treatment hardness is 140–180 HB.
  • Stainless steel components (ball, stem): Solution annealing (1040–1150℃, water-cooled) to restore corrosion resistance.
• Descaling & Cleaning: Forged parts are shot-blasted to remove surface oxide scale, then cleaned with ultrasonic baths to eliminate residual contaminants.

C. Precision Machining

• Body & Bonnet Machining: CNC lathes and mills process flange faces, seat pockets, and stem bores. Flange faces are machined to flatness ≤0.02mm/m and surface roughness Ra 1.6μm. Seat pockets are honed to coaxiality ≤0.01mm relative to the bore, ensuring uniform ball-seat contact.
• Ball Machining: Forged balls are ground to spherical accuracy ≤0.005mm and lapped to Ra ≤0.4μm. Full-port bores are machined to match pipeline dimensions, with no sharp edges to minimize flow turbulence. Optional Stellite overlay is applied via welding and ground to precise dimensions.
• Stem Machining: Stems are turned and ground to diameter tolerance ±0.01mm and polished to Ra ≤0.4μm. The anti-blowout shoulder is precision-machined to engage the body securely.

D. Assembly & Comprehensive Testing

1. Component Cleaning: All parts (body, ball, seats, stem, packing) are degreased and ultrasonic-cleaned to remove oil, debris, and metal particles—preventing contamination of sealing surfaces.
2. Assembly Sequence: The floating ball is installed first, followed by the seats (with preloaded springs), stem, packing, and bonnet. Fasteners are tightened in a crisscross pattern to uniform torque (per ASME B18.2.1) to ensure even clamping force.
3. Pressure Testing:
   • Hydrostatic Shell Test: 1.5× rated pressure applied to the body cavity for 30 minutes—no leakage, deformation, or pressure drop permitted.
   • Hydrostatic Seat Test: 1.1× rated pressure applied to each seat (bidirectional) for 15 minutes—leakage measured via bubble counting, complying with ANSI/FCI Class IV/VI.
   • Pneumatic Test (Optional): 0.6MPa air pressure applied to the body and seats for 10 minutes—no audible leakage permitted.
4. Operational Testing: The valve is cycled 50 times (open-close) to verify smooth operation, consistent torque, and correct actuator performance (for pneumatic/electric models).
5. Specialized Testing:
   • Fugitive Emissions Test: ISO 15848-1 Class AH compliance verified with methane and flame ionization detector (FID).
   • Sour Service Test: For NACE MR0175-compliant valves, testing in H₂S-containing media to confirm corrosion resistance.

E. Final Inspection & Packaging

• Visual Inspection: Each valve is inspected for surface defects (scratches, dents), proper machining, and correct marking (DN, PN, TIANYU logo, certifications). Valves with surface scratches deeper than 0.05mm are rejected.
• Documentation: Each valve is shipped with a Documentation Package including MTC, Hydrostatic Test Certificate, EN10204 3.1/3.2 Certificate, and CE PED Declaration of Conformity.
• Packaging: Valves are packaged in plywood crates with foam insulation to prevent damage during transportation. Flange ends are capped with plastic protectors, and actuators are wrapped in waterproof film. Crates are labeled with handling instructions and product information for safe delivery.