DN500 Pneumatic Motorized Double Eccentric butterfly Valve Pn16 High-Performance Double-Offset Butterfly Valve

Specification

TIANYU High-Performance Double-Offset Butterfly Valve: All-round Solution for Industrial Fluid Control

I. Product Overview

As a core device for precise flow regulation and reliable shut-off in industrial pipeline systems, the TIANYU high-performance double-offset butterfly valve features an innovative double-offset structure, constructed from high-performance materials such as ductile iron, cast steel, and stainless steel, paired with electric, pneumatic, or manual drive systems for versatile complex applications. With a diameter range of DN50-DN1200 (2″-48″) and pressure ratings of PN10-PN40 (Class 150-600LB), it stably controls media like water, steam, oil, gas, and acid-base solutions within -40°C-400°C, complying with international standards such as API 609, EN 593, and GB/T 12238. It serves as an ideal choice for petrochemical, power energy, municipal water supply/drainage, and metallurgical mining sectors.

II. Core Features: Double-Offset Technology and Full-condition Adaptability

Double-Offset Structural Design
- Eccentric Principle: The stem axis deviates from both the seat centerline and disc plane (radial offset 2-3mm, angular offset 5°), enabling the disc to disengage from the seat rapidly when opening, reducing seal surface friction by 60% compared to ordinary butterfly valves and significantly extending service life.
- Bidirectional Sealing: Combining metal hard seal (Stellite overlay welding) with elastic soft seal (EPDM/NBR/PTFE) achieves bidirectional bubble-tight sealing (API 598 standard leakage ≤0.01×DN mm³/s) without distinguishing media flow direction.
- Torque Optimization: The double-offset design reduces opening/closing torque by 40%, with pneumatic actuation torque for DN300 ≤120N·m, suitable for low-power drive systems and delivering significant energy savings.
Diversified Material System
- Ductile Iron (QT450-10): Tensile strength ≥450MPa, elongation ≥10%, suitable for normal-temperature low-pressure conditions (e.g., municipal water supply/drainage), with epoxy coating thickness ≥200μm passing salt spray tests ≥1000 hours.
- Cast Steel (WCB): Yield strength ≥250MPa, resistant to 425°C high-temperature steam, applicable to high-temperature/high-pressure scenarios in thermal power plants and refineries.
- Stainless Steel (304/316): Containing 18% chromium and 8% nickel (316 with 2% molybdenum), offering 8x higher chloride corrosion resistance than carbon steel, suitable for seawater and chemical media.
Intelligent Drive and Control
- Actuator Configuration: Electric actuators support 4-20mA analog regulation, with IP68 protection and explosion-proof type complying with Ex d IIBT4 standards; pneumatic actuators respond within ≤0.8 seconds with spring return function.
- Remote Monitoring: Integrated with communication protocols like Modbus/TCP and Profibus DP, enabling real-time position feedback, fault diagnosis, and remote control via SCADA systems.
- Manual Backup: Equipped with worm gear manual mechanism, allowing easy switching to manual operation during power outages or failures to ensure system safety.

III. Key Attributes: Technical Parameters and Standard Compliance

Attribute Category	Specific Parameters
Diameter Range	DN50-DN1200 (2″-48″), supporting non-standard customization (max DN2000)
Pressure Rating	PN10/16/25/40 (Class 150/300/600/900LB), compliant with ASME B16.34 pressure-temperature ratings
Body Material	QT450-10 ductile iron, WCB cast steel, CF8 (304)/CF8M (316) stainless steel, duplex stainless steel 2205 (optional)
Seal Material	Main seal: Stellite (metal hard seal); Auxiliary seal: EPDM (-20°C-120°C), NBR (-40°C-100°C), PTFE (-100°C-260°C)
Connection Type	Wafer, Flange, Lug, compliant with ANSI B16.5 and DIN EN1092-1 standards
Actuation Method	Electric (intelligent), pneumatic (double-acting/single-acting), manual (worm gear), supporting explosion-proof/fire-safe customization
Manufacturing Standards	Design: API 609, EN 593, GB/T 12238; Testing: API 598, ISO 5208; Certifications: CE, TSG A1 grade
Suitable Media	Clean water, sewage, steam, gas, crude oil, acid-base solutions (pH 2-12), particle-containing media (≤50μm particle size)

Product Overview

IV. Manufacturing Processes: Precision Control from Material to Finished Product

Material Forming and Treatment
- Ductile Iron Melting: Using cupola-electric furnace dual process, adding rare earth magnesium alloy nodulizer to ensure nodulization rate ≥90%, graphite sphere diameter ≤0.05mm, and annealing at 900°C to eliminate internal stress.
- Stainless Steel Casting: Vacuum induction melting, passing intergranular corrosion test (ASTM A262 E method), with castings solution quenched at 1050°C to achieve grain size ≥Grade 5.
- Surface Treatment: Valve body sandblasted to Sa2.5, sprayed with AkzoNobel epoxy powder ≥200μm thick, adhering to ISO 2409 cross-cut test Grade 0.
Precision Machining and Assembly
- 5-Axis Machining: Disc and seat sealing surfaces processed by CNC grinder to surface roughness Ra≤0.4μm, flatness error ≤0.01mm, forming high-precision seal pairs.
- Stem Treatment: 2Cr13 stainless steel stem quenched and tempered (HRC28-32), chrome-plated 0.03-0.05mm for 5x wear resistance, ensuring 100,000 cycles without jamming.
- Actuator Calibration: Each valve undergoes 1.1x nominal pressure opening/closing test, with drive system and body matching accuracy ≤±0.5° to guarantee control precision.
Full-process Quality Control
- Material Certification: Each batch of steel provides spectral analysis, tensile test (e.g., WCB yield strength ≥250MPa), and impact toughness reports (-20°C impact energy ≥27J).
- Pressure Testing: Shell tested at 1.5x nominal pressure (e.g., 2.4MPa for PN16) for 15 minutes; seal testing at 1.1x nominal pressure with zero bidirectional leakage.
- Life Verification: 100,000 cycle tests ensure seal wear ≤0.05mm and torque decay ≤8%, far exceeding industry standards.

Valve Details

V. Product Advantages: Core Value in Industrial Scenarios

Long Service Life and Low Maintenance Costs
The double-offset structure reduces seal wear. A DN600 butterfly valve in a wastewater treatment plant operated for 10 years without seal replacement, extending maintenance cycles by 3 times and decreasing annual costs by 50%. Ductile iron body weight is 20% lighter than cast steel, reducing installation expenses.
Full-condition Adaptability
- Temperature Range: -40°C low-temperature LNG pipelines (LCB low-temperature steel) to 400°C high-temperature thermal oil systems (WCB cast steel + metal hard seal), covering wide temperature ranges through material combinations.
- Media Compatibility: 316 stainless steel body resists seawater (Cl⁻≤2000ppm), duplex steel 2205 withstands sour crude oil (pH≥4), meeting requirements of multiple industries.
Customized Solutions
- Industry-specific Customization:
  - Food & pharmaceutical: 316L stainless steel + FDA-certified PTFE seal supporting CIP/SIP online cleaning.
  - Nuclear auxiliary systems: Compliant with ASME BPVC Section III, offering 1E-level seismic design.
  - Metallurgy & mining: Wear-resistant tungsten carbide-coated discs for gas pipelines with dust content ≤50mg/m³.
- Functional Expansion: Special designs including fire-safe (API 607 certified), H₂S-resistant (NACE MR0175), and cryogenic (-196°C liquid nitrogen dedicated) to meet harsh conditions.
Global Service Support
Exported to 60+ countries, validated in Middle Eastern refineries (500°C high-temperature cracking gas), European drinking water projects (WRAS certified), and Southeast Asian offshore platforms (seawater corrosion environments). Providing 7×24-hour technical response, overseas warehouses covering major ports, regular accessories delivered within 48 hours, and emergency orders expedited via multi-line production.

Application

VI. Application Fields: In-depth Industry Coverage

Petrochemical Industry
- Flow regulation for oil-gas pipelines in atmospheric-vacuum distillation units, metal hard seals resisting coking and high-temperature erosion.
- Reactor inlet/outlet control in chemical plants, 316 stainless steel resisting organic solvents like methanol and benzene.
Power Energy Sector
- Flow distribution for circulating water systems (DN1000) in thermal power plants, pneumatic actuators enabling automatic regulation with DCS systems.
- Nuclear power plant auxiliary pipelines, duplex steel bodies meeting nuclear-grade water quality requirements for safe operation.
Municipal Environmental Protection
- Sectional shut-off for urban water main pipes, ductile iron body offering cost-effectiveness, surface coating compliant with drinking water standards.
- Aeration systems in wastewater treatment plants, EPDM seals resisting ozone corrosion for precise air flow regulation.
Metallurgy and Mining
- Fast shut-off for blast furnace gas pipelines, wear-resistant seals reducing dust jamming to ensure safe production.
- Mineral slurry transportation in concentrators, tungsten carbide-coated discs extending service life by 3 times and reducing downtime.