The valve’s core advantage lies in its 3-way design, which integrates three ports (A, B, C) to enable two critical functions: L-type diversion (directing gas from port A to B or A to C) and T-type convergence (mixing gas from A and B into C). This eliminates the need for multiple 2-way valves in gas distribution systems—for example, in a natural gas network, it can divert gas from a main line to either a residential supply or an industrial branch, simplifying pipeline design and reducing installation costs. The ball’s precision-machined flow paths ensure minimal pressure drop (≤0.05MPa at rated flow), preserving gas system efficiency.
Equipped with a compact electric actuator, the valve supports remote operation via control signals, making it ideal for unmanned gas stations or industrial plants with centralized control systems. The actuator’s on-off mode enables quick shut-off in emergencies (e.g., gas leak detection), while modulating control allows fine-tuning of gas flow rates—critical for processes like gas mixing in chemical plants, where precise ratios of inert and reactive gases are required. A manual override function ensures operability during power outages, enhancing reliability in safety-critical applications.
Unlike flanged valves, the threaded design allows installation in tight spaces (e.g., wall-mounted gas meters, confined machinery). Precision-machined NPT/BSPT threads create a metal-to-seal connection when paired with thread sealant (e.g., PTFE tape), eliminating leakage risks common in poorly aligned flanged joints. This design also simplifies retrofitting into existing threaded pipelines, reducing downtime during upgrades—essential for municipal gas networks where service interruptions must be minimized.
The valve’s seat uses PTFE as standard, a material with low gas permeability and chemical inertness, ensuring bubble-tight sealing for non-aggressive gases (natural gas, nitrogen). For gas-water mixtures (e.g., humid industrial gases), EPDM seals offer superior elasticity and water resistance. In high-temperature scenarios (e.g., heated process gases), FKM seals maintain integrity up to 200℃, avoiding hardening or cracking that could cause leaks. The seat is mechanically retained to prevent displacement under gas pressure surges, a critical feature in fluctuating gas systems.
Stainless steel 304/316 construction resists corrosion from moisture, mild acids, and chloride ions—key for gas systems where condensation or trace contaminants (e.g., hydrogen sulfide in natural gas) could degrade carbon steel valves. In coastal areas or industrial zones with high humidity, 316 stainless steel prevents pitting corrosion, extending valve service life to 10+ years. The ball’s smooth, polished surface (Ra ≤0.8μm) minimizes gas turbulence, reducing erosion and ensuring consistent flow characteristics.
- Stainless Steel Sourcing: 304/316 billets are sourced from certified mills, with chemical composition verified via spectral analysis (e.g., 304: 18-20% Cr, 8-10.5% Ni) to ensure corrosion resistance.
- Defect Detection: Billets undergo ultrasonic testing to identify internal flaws (porosity, cracks) that could compromise pressure integrity in gas service.
- Body & Threads: The valve body is CNC-turned to form the 3-way flow paths, with threads machined to NPT/BSPT standards (tolerance ±0.02mm) using thread rolling—enhancing thread strength and leak resistance compared to cutting.
- Ball Fabrication: The 3-way ball is CNC-machined to create L-type or T-type flow channels, with surface grinding to achieve Ra ≤0.8μm. This ensures uniform contact with the seat, critical for gas tightness.
- Stem Machining: The stem is precision-ground to fit the body’s packing chamber, with a keyway to connect securely to the actuator, ensuring torque transmission without slippage.
- Seat Installation: PTFE/EPDM/FKM seats are compression-molded to match the ball’s contours, then press-fitted into the body’s seat pockets. Retaining rings prevent seat displacement under gas pressure.
- Packing Assembly: Graphite-impregnated PTFE packing is wrapped around the stem to form a gas-tight seal, compressed to balance leak resistance and smooth stem rotation.
- Actuator Mounting: The electric actuator is bolted to the valve body via an ISO 5211 mounting pad, with the drive shaft connected to the valve stem via a spline coupling—ensuring precise alignment for 90° rotation.
- Wiring & Calibration: Actuator wiring is tested for continuity, and control signals (4-20mA for modulating type) are calibrated to ensure flow rate corresponds linearly with valve rotation (e.g., 4mA = 0% open, 20mA = 100% open).
- Gas Leak Test: Under 1.1×PN16 (1.76MPa) nitrogen pressure, the valve undergoes bubble testing—no visible bubbles indicate ANSI/FCI Class VI compliance.
- Hydrostatic Test: The body is pressurized to 1.5×PN16 (2.4MPa) with water for 30 minutes, verifying structural integrity.
- Cycle Test: 10,000+ open-close cycles are performed with gas media to validate actuator reliability and seat durability, with torque measurements recorded to ensure consistent operation.
- Thread Seal Test: Assembled with a threaded pipe fitting, the valve is pressurized to PN16 to confirm no leakage at the thread joint—critical for gas systems where even minor leaks pose safety risks.
