Ductile Iron/Cast Steel Electric Flanged Double Eccentric Soft Seal Butterfly Valve

Specification

TIANYU Ductile Iron/Cast Steel Electric Flanged Gate Valve: Industrial Pipeline Control Solution

I. Product Overview

As a critical shut-off device in industrial pipeline systems, the TIANYU electric flanged gate valve is constructed from ductile iron or cast steel, combined with rising stem (OS&Y) or non-rising stem structures, and achieves automated control via electric actuators. With a diameter range of DN50-DN1200 (2″-48″) and pressure ratings of PN10-PN40, it stably controls various media including water, steam, oil, and gas within -20°C-450°C. Widely used in water supply/drainage, power, chemical, and metallurgy sectors, it complies with international standards such as API 6D, ASME B16.34, and GB/T 12234.

II. Core Features: Structural Optimization and Material Upgrades

Elastic Double-Gate Design
- Sealing Principle: The elastic double-gate structure forms a line contact between the gate and seat, automatically compensating sealing specific pressure via medium pressure to achieve ANSI B16.104 Class VI sealing.
- Self-Cleaning Function: During opening/closing, relative movement between the gate and seat scrapes deposits from sealing surfaces, suitable for particle-containing media.
- Pressure Balancing: The gate features balancing holes to reduce operating torque. The electric actuation torque for DN600 is ≤800N·m, reducing energy consumption by 20% compared to similar products.
Upgraded Material System
- Body Materials: Ductile iron (QT450-10) with tensile strength ≥450MPa and elongation ≥10% suits normal-temperature low-pressure conditions; cast steel (WCB) with yield strength ≥250MPa applies to high-temperature/high-pressure systems.
- Seal Surface Treatment: Seat sealing surfaces are overlay-welded with Stellite 6 alloy, hardness ≥HRC45, enhancing erosion resistance by 5 times.
- Surface Protection: The body uses epoxy coating (thickness ≥250μm), passing salt spray tests ≥1,500 hours without rust, compliant with drinking water standards (WRAS certified).
Intelligent Drive System
- Electric Actuator: Integrated smart electric actuator with IP68 protection and Ex d IIBT4 explosion-proof rating, supporting 4-20mA analog control.
- Remote Monitoring: Integrated with Modbus/TCP and Profibus DP protocols for remote on/off control, position feedback, and fault diagnosis.
- Manual Backup: Equipped with manual operation mechanism to ensure safety during power outages or failures.

III. Key Attributes: Technical Parameters and Standard Compliance

Attribute Category	Specific Parameters
Diameter Range	DN50-DN1200 (2″-48″), supporting non-standard customization (max DN1600)
Pressure Rating	PN10/PN16/PN25/PN40, compliant with ASME B16.5 and EN 1092-1 flange standards
Body Material	QT450-10 ductile iron, WCB cast steel, LCB low-temperature steel (optional)
Seal Material	NBR, EPDM, PTFE, metal hard seal (high-temperature type)
Connection Type	Flanged (RF/FF), compliant with ISO 7005-1 and GB/T 9113 standards
Actuation Method	Electric (standard), pneumatic (optional), manual (backup)
Manufacturing Standards	Design: API 6D, ASME B16.34, GB/T 12234; Testing: API 598, ISO 5208; Certifications: CE, TSG
Suitable Media	Clean water, sewage, steam, gas, oil products, weak acid-base solutions (pH 4-10)

Product Overview

IV. Manufacturing Processes: Precision Control from Melting to Finishing

Melting and Forming
- Ductile Iron Melting: Cupola-electric furnace dual melting controls Mg content (0.03%-0.06%) to ensure spheroidization rate ≥90% and graphite sphere diameter ≤0.05mm.
- Cast Steel Refining: Electric arc furnace melting + LF refining with S/P ≤0.035%, resin sand molding achieves CT7-level dimensional accuracy.
- Heat Treatment: Castings undergo 900°C normalizing + 600°C tempering to eliminate internal stress and improve metallographic uniformity.
Precision Machining and Assembly
- CNC Machining: Gantry 5-axis machining centers ensure IT6-level accuracy for seat sealing surfaces, with surface roughness Ra≤0.4μm.
- Gate Treatment: Gates with Stellite overlay welding undergo vacuum quenching, hardness ≥HRC48, sealing surface flatness ≤0.02mm.
- Assembly Testing: Each valve undergoes 1.5x nominal pressure shell testing and 1.1x seal testing; electric actuators are debugged for 50 cycles without jamming.
Quality Inspection System
- Nondestructive Testing: Magnetic particle inspection (MT) for gate surface cracks; ultrasonic testing (UT) for valve body internal defects.
- Material Certification: Each batch provides spectral analysis reports and tensile test data (ductile iron yield strength ≥310MPa).
- Life Verification: 10,000 cycle tests ensure seal wear ≤0.08mm and torque variation ≤8%.

Valve Details

V. Product Advantages: Core Competitiveness in Industrial Scenarios

Long Service Life and Reliability
The elastic double-gate structure reduces seal wear. A DN400 gate valve in a power plant operated for 10 years without seal replacement, reducing maintenance costs by 55% compared to ordinary gate valves.
Cost-Effectiveness Optimization
- Initial Investment: Ductile iron bodies cost 30% less than cast steel valves, with DN600 models offering a price advantage of ¥28,000.
- Installation Cost: 18% lighter weight reduces lifting and foundation costs by 35%.
- Operation Energy Consumption: Electric actuator power is 25% lower than similar products, saving ~12,000 kWh annually (DN800 model).
Customized Solutions
- Condition Adaptation: High-temperature graphite packing (≤550°C) for high-temperature conditions; LCB material (-46°C) for low-temperature scenarios.
- Functional Expansion: Fire-safe (API 607 certified), H₂S-resistant (NACE MR0175), and wear-resistant (hard alloy sealing surfaces).
- Connection Customization: Supports JIS, ANSI, ASME, etc., with non-standard flanges machined to drawings.
Global Service Support
Exported to 50+ countries, with 6 major warehouses in Europe, the Middle East, and Southeast Asia for 48-hour emergency response. Offering full lifecycle management, including selection consultation, installation guidance, and fault diagnosis.

Application

VI. Application Fields: Multi-industry Fluid Control Coverage

Municipal Water Supply/Drainage
- Trunk pipe shut-off for urban water supply, DN1000 models for long-distance water transmission.
- Sludge transportation in wastewater treatment plants, wear-resistant seals extend service life.
Power Industry
- Main steam pipeline shut-off (450°C, 10MPa) in thermal power plants, metal seals resist high-velocity steam erosion.
- Nuclear power plant secondary circuit condensate systems, compliant with ASME BPVC Section III nuclear standards.
Metallurgy and Mining
- Fast shut-off for blast furnace gas pipelines, H₂S-resistant design (H₂S partial pressure ≤1MPa).
- Mineral slurry transportation in concentrators, wear-resistant coated gates extend life by 4x.
Chemical and Petrochemical
- Oil transportation pipelines in refineries, high-temperature/high-pressure resistance (425°C, PN40).
- Reactor inlet/outlet in chemical plants, corrosion-resistant materials (316L stainless steel) for acid-base environments.