III. Feature Description

A. Floating Ball Design: Optimized for Small-Bore Applications

• Self-Sealing Mechanism: Unlike trunnion-mounted ball valves (which require fixed supports for the ball), the floating ball relies on media pressure to press the ball against the outlet-side valve seat. This eliminates the need for upper and lower trunnions, reducing the valve’s complexity, weight, and manufacturing cost—critical advantages for small-bore, low-cost applications.
• Compact Footprint: The absence of trunnion supports allows the valve to maintain a short face-to-face length (90mm for DN15), making it suitable for installation in tight spaces (e.g., between equipment components or in laboratory setups where space is limited).
• Bidirectional Sealing: The floating ball design enables reliable sealing in both flow directions, eliminating the need for check valves and simplifying pipeline layout. This is particularly valuable in systems where media flow may reverse (e.g., small-scale recirculation loops in food processing).

B. All-SS304 Wetted Components: Hygiene & Corrosion Resistance

• Hygienic Compatibility: SS304 is non-toxic, non-reactive, and easy to clean—making it suitable for food, beverage, and potable water applications. The polished surface (Ra ≤0.8μm) of the wetted components prevents media adhesion and bacterial growth, ensuring compliance with FDA and HACCP standards.
• Corrosion Resistance: SS304 resists rust and degradation from mild corrosive media, including chlorinated water (municipal water supplies), dilute acetic acid (food processing), and sodium bicarbonate solutions (industrial cleaning). This eliminates the need for frequent valve replacement due to corrosion, reducing lifecycle costs.

C. PTFE Soft Seal: Bubble-Tight Closure & Chemical Inertness

• Bubble-Tight Sealing: Class VI sealing prevents even minute leaks, protecting high-value media (e.g., specialty food ingredients) from loss and ensuring pure media (e.g., lab reagents) remain uncontaminated.
• Chemical Compatibility: PTFE is inert to nearly all non-oxidizing media, making the valve suitable for handling water, air, food-grade oils, dilute acids, and weak alkalis. This versatility eliminates the need for multiple valve types across different process lines.
• Low-Friction Operation: PTFE’s self-lubricating properties reduce operating torque, enabling easy manual lever operation even for users with limited physical strength.

D. Manual Lever Operation: Simplicity & Reliability

• Power-Independent Control: Unlike pneumatic or electric valves, the lever requires no external energy source—ideal for remote locations, laboratory setups, or small-scale systems where power access is limited.
• Intuitive Operation: The 90-degree rotation provides clear, immediate visual confirmation of valve position, reducing the risk of human error (e.g., leaving the valve partially open). The anti-slip grip ensures secure handling even in wet or greasy environments (common in food processing).
• Low Maintenance: The lever has no moving parts beyond the rotational joint, eliminating the risk of actuator failure or electrical component malfunction. Routine maintenance is limited to lubricating the joint (annually) and inspecting the grip for wear.

E. Standardized Design: Interchangeability & Easy Installation

• Flange Compatibility: ASME B16.5 Class 150 flanges match standard pipeline components, eliminating the need for custom fabrication or adapters.
• Face-to-Face Interchangeability: API 608-compliant dimensions mean the valve can replace existing ball valves from other manufacturers without modifying the pipeline layout.
• Regulatory Compliance: CE PED certification ensures the valve meets European safety standards for pressure-containing equipment, while FDA compliance enables use in food and beverage applications worldwide.

IV. Manufacturing Process & Quality Control

A. Raw Material Procurement & Inspection

• SS304 Procurement: SS304 billets and plate 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 SS304 components undergo spectral analysis (XRF) to confirm compliance with ASTM A182/A276 standards. Tensile and impact tests are performed on sample specimens to verify mechanical properties (e.g., tensile strength ≥515MPa).
• PTFE Validation: PTFE resin is tested for purity (≥99.5% PTFE), tensile strength (≥20MPa), and compliance with FDA 21 CFR 177.1550. Resin batches that fail any test are rejected to prevent contamination risks.
• Non-Destructive Testing (NDT): Forged SS304 body and ball components undergo ultrasonic testing (UT) to detect internal defects (e.g., cracks, inclusions) and magnetic particle testing (MPI) to inspect surface flaws. Only defect-free components proceed to machining.

B. Forging & Machining

• Cold Forging: SS304 billets are cold-forged into body and ball blanks using a 500-ton hydraulic press. Cold forging (performed at room temperature) ensures a dense, uniform grain structure, enhancing mechanical strength and corrosion resistance compared to casting. The forging ratio is maintained at ≥3:1 to eliminate internal voids.
• CNC Machining: Blanks are processed on 5-axis CNC lathes and mills to meet ASME B16.34 dimensional tolerances:
  • Valve Body: The flange faces are machined to a flatness tolerance of ≤0.02mm/m and a surface roughness of Ra ≤1.6μm. The seat groove is machined to a depth tolerance of ±0.02mm to ensure a tight fit for the PTFE seat.
  • Ball: The ball is precision-ground to a spherical accuracy of ≤0.005mm, with the sealing surface lapped to a roughness of Ra ≤0.4μm to ensure uniform contact with the PTFE seat. The full-port bore is machined to match the DN15 pipeline diameter.
  • Stem: The stem is turned to a diameter tolerance of ±0.01mm, with the anti-blowout shoulder machined to engage the body’s bonnet bore. The surface is polished to Ra ≤0.4μm to minimize packing friction.

C. Surface Treatment & Passivation

• Passivation: SS304 components undergo nitric acid passivation (per ASTM A967) to form a protective chromium oxide layer on the surface. This layer prevents rust and bacterial adhesion, critical for hygiene-critical applications. Passivation is followed by thorough rinsing with deionized water to remove acid residues.
• Polishing: Wetted surfaces (body cavity, ball, stem) are polished to a roughness of Ra ≤0.8μm using a multi-step process: rough grinding to remove machining marks, fine grinding to refine the surface, and final polishing with food-grade abrasives to ensure hygiene.

D. Assembly & Comprehensive Testing

1. Component Cleaning: All parts (body, ball, stem, seat, packing) are cleaned in an ultrasonic bath with food-grade detergent, then rinsed with deionized water and dried in a HEPA-filtered oven. This eliminates oil, debris, and metal particles that could contaminate process media.
2. Seat Installation: The PTFE seat is pressed into the body’s seat groove using a hydraulic press (5kN force) to ensure uniform contact. For food-grade applications, the seat is bonded to the groove using FDA-compliant adhesive.
3. Stem & Ball Assembly: The stem is inserted into the body’s bonnet bore, then connected to the ball via a keyway (secured with a stainless steel retaining ring). The multi-layer packing assembly is installed around the stem, with each layer compressed to the specified torque to balance sealing and operational torque.
4. Lever Attachment: The aluminum lever is bolted to the stem’s top end, with a set screw to lock it in place. The lever is adjusted to ensure a full 90-degree rotation (open = lever parallel to the pipeline; closed = lever perpendicular).

• Hydrostatic Shell Test: 1.5× rated pressure (2.4MPa) is applied to the valve body cavity for 30 minutes. No leakage, deformation, or pressure drop is permitted.
• Hydrostatic Seat Test: 1.1× rated pressure (1.76MPa) is applied to each flow direction for 15 minutes. Leakage is measured via the bubble method (submerging the valve in water), with Class VI compliance requiring ≤1 bubble per minute.
• Operational Test: The valve is cycled 50 times (open-close) to verify smooth rotation, consistent torque, and correct lever alignment.
• Hygiene Validation (Food-Grade Units): Sample valves undergo swab testing for bacterial contamination (E. coli, Salmonella) after assembly. No contaminants are permitted.

E. Final Inspection & Packaging

• Visual Inspection: Each valve is inspected for surface defects (scratches, dents), proper polishing, and correct marking (DN15, PN16, TIANYU logo, standard certifications). Valves with surface scratches deeper than 0.05mm are rejected (scratches can trap bacteria).
• Documentation: Each valve is shipped with a Documentation Package including a Material Test Report (MTR) for SS304 components, a Hydrostatic Test Certificate, an FDA Compliance Certificate (for food-grade units), and a CE PED Declaration of Conformity.
• Hygienic Packaging: Valves are wrapped in food-grade polyethylene film, with flange ends capped with sterile plastic protectors to prevent contamination during transportation. The package is labeled with handling instructions (e.g., “Keep Clean”) to ensure hygiene is maintained until installation.