Specification

TIANYU Double Flanged Gear Operated Concentric Butterfly Valve: An Efficient Solution for Industrial Fluid Control

I. Product Technical Positioning and Core Parameters

The TIANYU double flanged gear operated concentric butterfly valve is specially designed for medium-high pressure fluid control, covering nominal diameters from DN50 to DN2000 (2″ to 80″) and suitable for pressure classes PN10/PN16 (1.0/1.6MPa). Its core structure adopts a concentric central line design (with the stem, disc, and pipeline axis coaxial), combined with double flanged connections (complying with standards like EN 1092 and ASME B16.5) to ensure seamless integration with pipeline systems. Driven by a worm gearbox, it supports manual operation or integration with electric/pneumatic actuators, suitable for media such as water, air, and oil within the temperature range of -20°C to 120°C.

II. Analysis of Core Technical Features

(A) Advantages of Concentric Structure and Double Flanged Design

Low-Resistance Efficient Flow Path:
The concentric layout keeps the disc parallel to the fluid direction when fully open, with the flow resistance coefficient Cv increased by 20% (pressure loss of DN300 valve ≤0.3m water column), especially suitable for large-flow scenarios (e.g., urban water transmission main lines).
Reliability of Double Flanged Connection:
The flanges at both ends of the valve body are directly fixed to the pipeline by bolts. Compared with wafer-type structures, they can withstand higher axial stress, avoiding displacement risks in vibration environments (e.g., pump inlets/outlets, compressed air pipelines).
90° Precise On-Off Control:
The gearbox drive ensures an on-off angle error ≤1°, combined with a mechanical limit device to achieve zero over-travel and visualized status (handle position corresponds to the opening degree), reducing the risk of misoperation.

(B) Sealing System and Material Science

Breakthrough in Soft Sealing Technology:
- Sealing Materials: Standard configurations include EPDM rubber (complying with WRAS drinking water certification), NBR nitrile rubber (oil-resistant), or PTFE polytetrafluoroethylene (corrosion-resistant), passing bi-directional bubble-tight zero-leakage tests (EN12266 Class A standard).
- Lifespan and Maintenance: The valve seat is fixed by a dovetail groove or pressure ring, supporting online replacement without pipeline disassembly, reducing maintenance costs by 35%.
Valve Body Material Combination:
- Main Materials: WCB cast steel (compressive strength ≥485MPa), ductile iron (QT450-10, elongation ≥10%), or 304 stainless steel (CF8, corrosion resistance increased by 3 times).
- Surface Treatment: The inner cavity and outer surface are coated with epoxy resin powder (thickness ≥200μm), passing salt spray tests (GB/T 10125, ≥1000 hours without corrosion), suitable for harsh environments like humidity and sewage.

(C) Analysis of Gear Drive System

Torque Transmission Optimization:
- Worm Gear Design: The reduction ratio is typically 1:20 to 1:50, with output torque reaching 27-9768 N·m (adjusted by diameter). The manual operation torque of DN200 valve ≤80N·m, enabling easy on-off by a single person.
- Self-Locking Function: The worm’s lead angle is smaller than the friction angle, ensuring the valve locks in any position to avoid accidental opening caused by medium pressure.
Mechanical Durability:
- Shaft System Strengthening: The stem uses 2Cr13 stainless steel with surface nitriding treatment (hardness HV≥700), combined with copper alloy bearings, capable of withstanding over 100,000 opening-closing cycles.
- Anti-Leakage Design: The stem seal adopts V-type PTFE packing + O-ring double protection, passing 1.5 times the nominal pressure test to ensure no external leakage during long-term operation.

III. Key Technical Parameters and Certifications

Parameter Category	Technical Indicators	Expansion Options
Nominal Diameter	DN50-DN2000	Custom DN2200+ (requires engineering evaluation)
Pressure Class	PN10/PN16	Upgraded to PN25/PN40
Body Material	WCB cast steel/ductile iron/304 stainless steel	316L stainless steel, duplex steel 2205 (corrosion-resistant scenarios)
Actuation Mode	Manual gearbox/electric/pneumatic	Explosion-proof electric (Ex d IIC T6), hydraulic drive
Sealing Standard	EN12266 Class A (zero leakage)	API 607 fire certification (metal seal redundancy design)
Testing Standard	API 598 (1.5x shell hydrostatic/1.1x sealing test)	Low-temperature test (-40℃, material upgraded to 304L)
Certification System	CE-PED, ISO 9001, WRAS (drinking water)	LR/DNV-GL classification, EAC (Russia)

Product Overview

IV. Manufacturing Processes and Quality Control

(A) Precision Processing Flow

Valve Body Casting and Treatment:
- WCB cast steel uses resin sand casting, followed by normalizing + tempering treatment to eliminate stress. The internal flow path is precisely milled by a CNC machining center with a roughness of Ra≤6.3μm.
- Stainless steel valve bodies use lost-wax casting with pickling and passivation to ensure corrosion resistance.
Disc and Stem Assembly:
- The disc passes dynamic balance testing (residual unbalance ≤10g·cm). The stem and disc are connected by involute splines (fit tolerance H7/g6) to prevent axial movement.
Sealing System Testing:
- Each valve must pass 1.5 times nominal pressure shell testing (30-minute hold without deformation) and 1.1 times sealing testing (helium leakage detection, leakage rate ≤5×10⁻⁸m³/s).
- Sampling for 100,000 opening-closing life tests with a sealing performance retention rate ≥95%.

(B) Quality Traceability and Certification

Material Traceability: All castings come with heat lot numbers and chemical composition reports, supporting third-party PMI testing; stainless steel materials provide intergranular corrosion test reports (ASTM A262 E method).
System Certifications: Passed ISO 9001 quality management, ISO 14001 environmental management, and OHSAS 18001 occupational health certifications. Export products comply with the EU CE-PED directive.
After-Sales Guarantee: Commit to a 12-month warranty period, providing free replacement for leakage caused by seal failure.

Valve Details

VI. TIANYU Brand Customization Advantages and Market Value

Relying on the technical accumulation of Wenzhou valve industry cluster, TIANYU has built full-chain customization capabilities to provide differentiated solutions for global customers:

(A) In-Depth Material and Structure Customization

Material Expansion: Can provide special materials such as Hastelloy C276 (acid-resistant), duplex steel 2205 (seawater-resistant), and fluorine lining (FEP/PFA) (strong corrosion-resistant), supporting corrosion simulation test reports.
Structure Optimization: For high-pressure (PN25/PN40), high-temperature (+200℃), or vacuum conditions, design metal hard seal + elastic compensation structure passing API 607 fire tests.
Drive Integration: Integrate intelligent electric actuators (with 4-20mA feedback), pneumatic diaphragm actuators (with positioners), or manual emergency devices to meet automated production line and explosion-proof area requirements.

(B) Rapid Certification and Compliance Response

International Certifications:
- European Market: Complete CE-PED certification within 7 working days and WRAS drinking water certification filing.
- North American Market: Provide UL certification and FM certification (fire protection applications), supporting ASME B16.5/B16.47 flange standards.
- Emerging Markets: EAC certification (Russia), GOST (CIS), etc., covering access requirements of “Belt and Road” countries.
Industry Customization:
- Marine Valves: Provide LR/DNV-GL classification society certifications, meeting IMO anti-pollution regulations (MEPC.176(58)).
- Nuclear Power Field: Execute RCC-M standards, with key components passing 1E-level seismic tests.

(C) Supply Chain and Delivery Assurance

Inventory and Production: Standard products (DN50-DN600) have 72-hour spot inventory, and small-batch customization (≥1 unit) production cycle is compressed to 7 working days. Emergency orders activate a 48-hour green channel.
Logistics and Service:
- Global Distribution: Achieve 3-5 working days delivery via DHL/FedEx, and support full-container sea shipping for bulk goods (direct shipping from Wenzhou Port).
- Localized Service: Establish technical centers in East China, South China, and Europe, providing on-site installation training, annual maintenance inspections, and 24-hour fault response. Critical spare parts are delivered within 48 hours domestically via bonded warehouses.

(D) Full Life Cycle Cost Optimization

Design Cost Reduction: Optimize flow path design through CFD fluid simulation to reduce energy consumption (Cv value increased by 10%-15%); adopt modular structures to reduce the number of non-standard components.
Maintenance Efficiency: Replaceable seal seats and disassembly-free maintenance design reduce downtime by 50%; gearbox lubricating grease life ≥5 years, reducing maintenance frequency.
Data-Driven: Provide a valve health monitoring system (optional), real-time monitoring of torque, temperature, and leakage data through IoT sensors for predictive maintenance.

Application

V. Typical Application Scenarios and Cases

(A) Municipal Water Supply and Drainage Systems

Water Transmission Main Lines: DN800 double flanged butterfly valves applied in a prefecture-level city water supply project. WCB cast steel body with EPDM sealing achieved 2 consecutive years of zero leakage under PN16 pressure, extending the maintenance cycle to 18 months.
Sewage Treatment: DN600 ductile iron valve bodies with epoxy coating anti-corrosion resist hydrogen sulfide corrosion in sewage pipelines, with on-off response time ≤15 seconds to meet rapid interception needs during the rainy season.

(B) Industrial Circulation Systems

Power Plant Cooling Water: DN1000 double flanged butterfly valves used in 300MW unit condenser circulating water pipes. WCB cast steel materials withstand 80℃ hot water scouring, and electric actuators (IP67 protection) 联动 with DCS systems for automatic flow regulation.
Petrochemical Pipelines: DN300 stainless steel butterfly valves (304 material) in refinery gas pipelines, with NBR sealing, pass API 598 airtightness tests to ensure safe control of flammable and explosive media.

(C) Construction and Energy

HVAC: DN200 double flanged butterfly valves installed in commercial complex chilled water pipe networks. EPDM sealing has a compression set ≤5% under 70℃ conditions, reducing system energy consumption by 15% compared to traditional gate valves.
Heating Pipe Networks: DN400 ductile iron butterfly valves used in district heating projects, achieving -10℃ to 120℃ temperature difference cycles under PN16 pressure. Gearboxes are equipped with antifreeze grease to ensure reliable winter operation.

(D) Special Working Conditions Expansion

Seawater Desalination: Custom DN500 double flanged butterfly valves using 316L stainless steel + PTFE sealing, certified by LR classification society, resistant to chloride ion corrosion in seawater media, with salt spray testing ≥2000 hours without corrosion.
Food and Medicine: DN100 stainless steel butterfly valves (sanitary polish) with FDA-certified EPDM sealing, applied in dairy production lines to meet CIP online cleaning requirements.

Soft Sealing Cast Iron Gear Operated Concentric Double Flanged Butterfly Valve