Double Acting Double Eccentric Pneumatic butterfly Valve for Steam Pipe and Steam Pipe in Valve

TIANYU Double-Offset Pneumatic Butterfly Valve: Precision Flow Control for Demanding Industrial Processes

In high-cycle applications requiring rapid isolation and precise modulation, traditional valves struggle with wear and response lag. TIANYU’s double-offset pneumatic butterfly valve—crafted from CF8M stainless steel with ISO 5211-compliant actuators—delivers zero-friction sealing, millisecond actuation, and corrosion immunity, setting new standards for chemical processing, power generation, and automated fluid systems.

Engineering DNA: Offset Geometry Revolution

The valve’s breakthrough dual-eccentric design eliminates seal degradation:

1. Axis 1 Offset: Stem positioned behind disc centerline, enabling cam-action unseating (85% friction reduction)

2. Axis 2 Offset: Stem axis angled from pipe center, creating crescent-shaped clearance during rotation
   Result: Seal contact only at full closure, achieving 200,000+ cycles (3× industry average)

Performance Optimized Components

Sealing System

• Disc: 316L stainless steel with plasma-transferred arc (PTA) Stellite 21 overlay (HRC 45-48)

• Seat: Reinforced PTFE encapsulated 17-4PH stainless steel spring carrier

• Zero-Leak Guarantee: ≤1×10⁻⁵ mbar·L/s helium leakage (ISO 5208 Rate A)

Actuation Package

• Pneumatic System: Double-acting cylinders with nickel-plated aluminum housing

  • Response Time: 0.3 sec for 90° rotation (DN300 @ 6 bar)

  • Fail-Safe Options: Spring-return (ATEX/IECEx certified)

• Position Feedback: Non-contact magnetic encoder (±0.25° accuracy)

Structural Integrity

• Stem: Solid 630 precipitation-hardened SS (1,100 MPa yield strength)

• Bearings: Self-lubricating Rulon®-lined bronze, rated for 250°C intermittent

Precision Manufacturing Workflow

Stage 1: Advanced Metallurgy

• Casting: Investment-cast CF8M bodies with ferrite content ≤5% (Schaeffler diagram controlled)

• Corrosion Defense: Electropolished to Ra 0.8μm + passivation per ASTM A967

Stage 2: Robotic Fabrication

1. Disc Machining: 5-axis CNC profiling with 0.02mm concentricity tolerance

2. PTA Overlay: Automated Stellite deposition under argon shield (2.1±0.1mm thickness)

3. Stress Relief: Solution annealing at 1,050°C followed by cryogenic stabilization