TIANYU PN10 DN400 WCB Stainless Steel 304/316L Large Diameter Three Eccentric Metal Sealing Pneumatic Butterfly Valve: Industrial-Grade Flow Control Solution for High-Demand Pipelines

I. Product Overview

II. Key Attribute Specifications

A. Dimensional & Pressure Parameters

• Nominal Diameter (DN): DN400 (16 inches), optimized for large-flow pipelines with design flow rates up to 1200 m³/h (water, 20℃), ensuring efficient fluid transfer without excessive pressure drop.
• Nominal Pressure (PN): PN10 (1.0MPa working pressure), with hydrostatic test pressure of 1.5×PN (1.5MPa) for shell integrity and 1.1×PN (1.1MPa) for seat sealing, compliant with industrial low-to-medium pressure system requirements.
• Temperature Range: -20℃~400℃, enabled by metal sealing (hard alloy surfacing) and high-temperature-resistant materials—suitable for ambient, heated, or high-temperature media (e.g., saturated steam, hot industrial wastewater).
• Connection Type: Flange-ended, conforming to international standards including GB/T 9115.1 (China), ASME B16.5 (USA), and EN 1092-1 (Europe). Flange face type: Raised Face (RF) as standard, ensuring compatibility with common pipeline gaskets (spiral-wound, non-asbestos).

B. Material Composition

• Valve Body: WCB cast carbon steel (ASTM A216), featuring tensile strength of 485~655MPa and yield strength of ≥240MPa. Ideal for non-corrosive media (water, air, mineral oil) and cost-sensitive large-diameter applications, with post-casting normalization heat treatment to relieve internal stresses.
• Butterfly Disc: 304 stainless steel (ASTM A182 F304, 18Cr-8Ni) as standard; 316L stainless steel (ASTM A182 F316L, 16Cr-10Ni-2Mo) optional for chloride-rich or mildly corrosive media (e.g., coastal municipal water, chemical dilute solutions). Disc thickness optimized for DN400 to resist deflection under PN10 pressure.
• Sealing System: Metal-to-metal sealing—seal face on disc and valve body surfacing with Stellite 6 (cobalt-based hard alloy, hardness ≥58 HRC) or WC (tungsten carbide, hardness ≥85 HRA). Ensures wear resistance and sealing integrity under high-temperature or abrasive conditions.
• Pneumatic Actuator: Aluminum alloy housing (6061-T6) with epoxy powder coating for corrosion resistance; internal piston and springs made of carbon steel (zinc-plated) or stainless steel (304) for durability.

C. Actuation & Performance Parameters

• Actuation Mode: Pneumatic drive, available in double-acting and spring-return (single-acting) configurations:
  • Double-acting: Compressed air (0.4~0.6MPa supply pressure) drives both opening and closing, 90° rotation time 15~30 seconds (adjustable via flow control valves).
  • Spring-return: Air drives one direction (e.g., opening), spring drives return (closing) for fail-safe operation (prevents media overflow during air supply loss).
• Control Signal: Optional 4~20mA analog signal for modulating control (0~100% flow adjustment) when paired with electro-pneumatic positioner; on-off control via 24V DC/220V AC solenoid valve as standard.
• Leakage Class: ANSI/FCI Class IV (metal sealing), allowing ≤0.01% of rated flow leakage—suitable for industrial applications where minimal media loss is acceptable (e.g., cooling water, process gas).
• Flow Coefficient (Cv): ≥1200 (DN400), indicating low flow resistance (full-port design) to reduce energy consumption of upstream pumps.

III. Feature Description

A. Three-Eccentric Structure: Solving Traditional Butterfly Valve Limitations

• When closing, the disc rotates and only contacts the seal face at the final 5°~10° of rotation, minimizing friction and wear.
• The conical seal face’s eccentricity ensures uniform pressure distribution across the seal, enhancing sealing reliability even with minor pipeline misalignment.

  For DN400 large-diameter applications, this design extends seal life by 2~3 times compared to double-eccentric butterfly valves, reducing maintenance frequency.

B. Metal Sealing: Adapt to High-Temperature & Abrasive Conditions

C. Pneumatic Actuation: Efficient Automation & Safety

• Double-acting actuators provide consistent torque (≥2000 N·m for DN400, PN10) to overcome large-diameter disc inertia, ensuring smooth opening/closing even under low air supply pressure (0.4MPa).
• Spring-return actuators offer fail-safe protection: In case of air pressure loss (e.g., compressor failure), the spring forces the valve to close (or open, per design) to isolate media—essential for safety-critical systems like chemical process lines or municipal water main isolation.

  Optional electro-pneumatic positioners allow precise flow modulation (e.g., adjusting cooling water flow to match power plant load), improving process efficiency.

D. Large-Diameter Design: High Flow Efficiency & Structural Stability

DN400’s full-port disc design (disc diameter matching pipeline inner diameter) minimizes flow resistance, with a Cv value of ≥1200—30% higher than partial-port large-diameter gate valves. This reduces pump energy consumption by 15%~20% in continuous-flow systems (e.g., municipal water distribution networks).

The WCB valve body features a thickened flange (≥20mm for DN400, PN10) and reinforced ribbing at the shaft bearing to resist deformation under pipeline pressure or external vibration—critical for large-diameter valves, which are more prone to structural stress than small-bore ones.

IV. Manufacturing Processes

A. Material Preparation & Quality Verification

• WCB Valve Body: Raw WCB billets undergo spectral analysis to confirm chemical composition (C: 0.25%~0.35%, Mn: 0.60%~1.00%) and ultrasonic testing (UT) to detect internal porosity or cracks. Casting is done via sand casting with resin-bonded sand, followed by normalization heat treatment (890~950℃, air cooling) to refine grain structure and relieve stresses.
• 304/316L Disc: Stainless steel plates are cut via laser (tolerance ±0.5mm) and forged to enhance density. Forged blanks undergo solution annealing (1050~1100℃ for 304, 1020~1080℃ for 316L) to restore corrosion resistance, then machined to final dimensions.

B. Precision Machining of Three-Eccentric Structure

• Eccentricity Machining: The disc’s three eccentricities are processed via 5-axis CNC milling centers, with dimensional tolerance controlled within ±0.03mm. A coordinate measuring machine (CMM) verifies eccentricity values after machining to ensure compliance with design standards.
• Seal Face Surfacing & Lapping: The disc and valve body’s seal faces are welded with Stellite 6 (via TIG welding) or sprayed with WC (high-velocity oxygen fuel, HVOF) to a thickness of 1.5~2.0mm. The seal faces are then lapped to a surface roughness of Ra ≤0.4μm using diamond abrasive, ensuring uniform contact during sealing.
• Shaft & Bearing Assembly: The valve shaft (304 stainless steel) is precision-ground to a diameter tolerance of h7 (±0.015mm) and assembled with self-lubricating bearings (bronze with PTFE inserts) to reduce rotational friction. The shaft’s axial and radial runout is tested to ≤0.05mm to avoid disc deflection.

C. Pneumatic Actuator Integration & Calibration

• Actuator Mounting: The actuator is mounted to the valve via an ISO 5211 adapter flange, with the drive shaft connected to the valve shaft via a spline coupling. Alignment is checked using a laser alignment tool to ensure 90° rotation without torque deviation.
• Torque Calibration: The actuator’s torque output is calibrated to match the valve’s required torque (≥2000 N·m for DN400, PN10). Flow control valves are adjusted to set opening/closing time (15~30 seconds), and the spring-return actuator’s spring force is tested to ensure fail-safe operation within 5 seconds of air loss.

D. Quality Testing & Certification

• Hydrostatic Shell Test: The valve body is filled with water and pressurized to 1.5MPa (1.5×PN10) for 30 minutes, with no visible leakage or deformation.
• Seal Leak Test: Under 1.1MPa (1.1×PN10) air pressure, the closed valve’s leakage is measured via a flow meter—ANSI/FCI Class IV compliance (≤0.01% of rated flow) is confirmed.
• Actuation Cycle Test: The valve undergoes 1000 open-close cycles with pneumatic actuation, checking for smooth operation, torque stability, and seal integrity after cycling.
• Material Certification: Each valve is accompanied by material test reports (MTRs) for WCB, 304/316L, and Stellite 6, ensuring compliance with ASTM/ASME standards.

V. Product Advantages

A. Long Service Life & Low Maintenance

B. High Adaptability to Harsh Conditions

C. Energy Efficiency & Cost Savings

D. Safety & Reliability

VI. Product Applications

A. Municipal Water & Wastewater

• Water Distribution Networks: DN400 valves are installed in municipal water mains to isolate sections for maintenance or regulate flow to residential/commercial areas. WCB body resists tap water corrosion, and metal seals withstand sediment in raw water.
• Wastewater Treatment Plants: Used in aeration tanks or effluent discharge lines—316L disc resists corrosion from chlorine-based disinfectants, and pneumatic actuation enables remote control to match treatment process loads.

B. Power Generation

• Thermal Power Plants: Controls cooling water flow in condenser circuits (180℃, PN10). Metal seals withstand hot water temperatures, and the low flow resistance reduces circulating pump energy use.
• Biomass Power Plants: Isolates saturated steam lines (190℃) in boiler auxiliary systems—spring-return actuators ensure valve closure during air loss to protect boiler pressure.

C. Chemical & Petrochemical

• Chemical Process Lines: Regulates flow of dilute acids (e.g., 5% sulfuric acid) or alkalis—316L disc and metal seal resist chemical corrosion, avoiding seal failure from soft material degradation.
• Petrochemical Storage Tanks: Used in crude oil or diesel tank outlet lines (ambient temperature, PN10). WCB body provides cost-effectiveness, and pneumatic actuation enables quick isolation during tank maintenance.

D. Metallurgy & Mining

• Steel Mills: Controls cooling water flow for blast furnaces—metal seals resist abrasion from water containing iron oxide particles, and the large Cv value ensures sufficient cooling water supply.
• Mining: Isolates tailings water lines (with fine ore particles)—316L disc resists corrosion from mineral-rich water, and the three-eccentric design prevents seal jamming from sediment.