Precision Flow Technology: Top-Tier Valve Series
Explore our precision-machined flow control series manufactured under stringent ISO 9001 and CE certifications, engineered to withstand aggressive pressures, corrosive dynamics, and rigorous cyclic operations.
China DI SS304 PN10/16 CL150 Double Flange Butterfly Valve
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OEM Two Shaft Replaceable Seat Double Flange Butterfly Valve
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China DI PN10/16 Class150 Soft Sealing Rising Stem Gate Valve
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China Split Body PTFE Coated Flange Type Butterfly Valve
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OEM Multy Standard Body Rubber Lined Disc Wafer Butterfly Valve
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China F4 Bolted Bonnet Soft Sealing Rising Stem OSY Gate Valve
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OEM Electric Actuator Flange Type Butterfly Valves
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China DN100 PN16 Wafer Butterfly Valve WCB Body
View SpecificationsExecutive Engineering Brief: The Mechanics of Double Flange Integrity
Industrial process plants, desalination facilities, and metropolitan water trunk lines encounter extreme thermal cyclic expansion, hydrostatic surges, and mechanical bending moments. Double flanged butterfly valves resolve structural vulnerabilities inherent in standard wafer and lug configurations through integral flange-to-flange structural stabilization.
Structural Independence & Rigidity
Unlike wafer configurations that depend on lengthy through-bolts subject to elongation under thermal strain, double flanged architectures feature discrete bolting circles at each end. This mechanical decoupling eliminates pipeline tension transfer, prevents body deflection, and permits full dead-end isolation service without downstream retention flanges.
Zero Fugitive Emissions & Sealing
Concentric and eccentric double flanged butterfly valves utilize engineered vulcanized elastomers (EPDM, NBR) or specialized Fluoropolymer liners (PTFE/PFA) encapsulated in robust ductile iron (QT450-10) or cast steel (WCB) bodies. Stem packing configurations incorporate dynamic chevron seals to surpass ISO 15848-1 tightness classes.
Hydrodynamic Optimization
Computer-optimized hydrodynamic disc contours minimize flow disturbance and turbulence coefficients (Cv/Kv enhancement). The symmetrical, low-profile lenticular disc reduces head loss and prevents cavitational pitting on downstream piping surfaces, extending operational asset lifespans across decades of municipal or industrial cycles.
China Factory 4.0: Supply Chain Resilience & Modern Manufacturing
Operating from our modernized manufacturing hub in Tianjin, China, Tianjin Zhongfa Valve Co., Ltd. (ZFA Valve) leverages automated precision casting, high-precision CNC machining centers, and digitized testing stations to achieve unmatched supply chain agility and cost-efficient OEM scalability.
Metallurgical Chemistry Control
Our captive foundry and partnered smelting facilities employ direct-reading optical emission spectrometers (OES) to evaluate every molten charge. Ductile Iron (EN-GJS-400-15 / ASTM A536 65-45-12) and WCB Cast Carbon Steels undergo systematic tensile, yield, and Charpy V-notch impact verification prior to machining.
Multi-Axis CNC Machining
Valve sealing faces, bearing housings, and flange serrated finishes (125-250 Ra RMS per ASME B16.5) are processed on dual-column CNC horizontal machining centers in single setup clampings, preserving concentricity tolerances within ±0.015mm to guarantee bubble-tight isolation.
Automated Electrostatic Coating
Corrosion mitigation is executed through continuous automated electrostatic fusion-bonded epoxy (FBE) application lines. Valve bodies receive preheating and uniform coating exceeding 250 microns (up to 300 microns for potable water systems per WRAS/NSF criteria) followed by holiday spark verification at 1.5 kV.
Digital Traceability & Testing
Every double flanged valve unit undergoes hydro-testing per EN 12266-1 / API 598 (Shell: 1.5× PN; Seat: 1.1× PN). Results are logged digitally against laser-etched heat and serialization barcodes, providing EPC procurement leaders with verifiable Material Test Reports (EN 10204 Type 3.1).
Macro Industry Solutions: Engineering Flow Dynamics
OEM Butterfly Valves with double flanges provide essential operational security across critical engineering environments where downtime produces catastrophic process losses.
Municipal Water Treatment & Desalination
Large-bore double flanged valves (DN400–DN2200) installed in reverse osmosis arrays, intake pumps, and potable water distributions. Constructed with ductile iron bodies, vulcanized EPDM liners, and duplex stainless steel (2205/2507) or aluminum-bronze discs resistant to chloride attack.
District Energy & Large-Scale HVAC
Managing chilled and high-temperature hot water circulation up to 130°C. Resilient seated concentric models with ISO 5211 direct-mount automation pads mate seamlessly with modulating electric rotary actuators, reducing plant energy usage via precision balancing.
Power Generation & Thermal Cooling Loops
Condenser cooling water isolation in combined-cycle gas turbine and coal power stations requires high Cv factors and resilience against vacuum collapse. ZFA double flanged butterfly valves maintain bidirectional bubble-tight sealing against reverse fluid shocks.
Technical Roadmap: Configuration, Materials & Standards
Review comprehensive dimensional and metallurgical specifications for our OEM Double Flanged Butterfly Valve portfolio. Custom drillings and alloys are supported for unique engineering designs.
| Engineering Parameter | Concentric Resilient Seated | Double Eccentric (High Performance) | Triple Eccentric (Metal Seated) |
|---|---|---|---|
| Nominal Diameter | DN50 – DN2400 (2" to 96") | DN100 – DN1800 (4" to 72") | DN80 – DN2000 (3" to 80") |
| Pressure Rating | PN10, PN16, Class 125, Class 150 | PN16, PN25, PN40, Class 150 / 300 | PN16 to PN100, ASME Class 150 to 600 |
| Body Materials | Ductile Iron (QT450-10, GGG40/50), WCB | WCB, LCC, CF8M, Duplex Stainless Steel | WCB, CF8M, CF3M, Hastelloy, Monel |
| Sealing System | Molded/Replaceable EPDM, NBR, PTFE | PTFE / R-PTFE / SS316 + Graphite Laminated | Stellite 21 hardfaced Seat + Multi-layer SS/Graphite |
| Working Temp. | -20°C to +120°C (EPDM), +82°C (NBR) | -50°C to +200°C | -196°C (Cryogenic) up to +550°C |
| Design Standards | EN 593, API 609 Cat. A, AWWA C504 | API 609 Cat. B, EN 593, ISO 10631 | API 609 Cat. B, ASME B16.34, BS EN 12516 |
| Face to Face Dim. | ISO 5752 Series 13 / 14, EN 558 Series 13/14 | ISO 5752 Series 13 / 14, EN 558 Series 13/14 | ISO 5752 Series 13 / 14, API 609 Long/Short |
Global Enterprise Procurement: Localized Assurance & Compliance
International EPC firms and global distribution networks require predictable delivery, rigorous technical vetting, and absolute regulatory compliance. ZFA Valve bridges tier-one factory pricing with international compliance governance.
Full Inspection Documentation (ITP)
We execute client-specified Inspection and Test Plans (ITP). Deliverables include Chemical and Mechanical Mill Test Reports (MTRs 3.1), Non-Destructive Testing (NDT via Radiographic/Dye Penetrant methods), Hydrostatic Pressure Charts, and Coating Thickness Verification Certificates.
OEM Customization & Actuation Sizing
From private labeling (custom body casting stamps, client nameplates) to custom polyurethane packaging for oceanic transport. Our automation center optimizes sizing for quarter-turn pneumatic, multi-turn electric, and hydraulic fail-safe actuators with matched brackets and splines.
Regulatory Audits & Environmental ESG
Tianjin Zhongfa Valve complies fully with Pressure Equipment Directive (CE-PED 2014/68/EU), ISO 9001:2015 Quality Systems, and global clean-air directives. We maintain transparent environmental practices across all foundry operations and powder coating lines.
Future Outlook: Digital Twins & Intelligent Valve Assemblies
The industrial valve sector is evolving from passive mechanical containment to active, intelligent IoT flow components. ZFA Valve invests continuously in research to address the next decade of infrastructure monitoring.
Embedded Diagnostic Torque Sensors
By embedding wireless strain sensors into the drive stem and yoke interface, our next-generation double flanged designs enable predictive asset monitoring. Anomalous torque spikes indicate early sediment encrustation, seat abrasion, or cavitation before catastrophic line failure occurs.
Advanced Polymeric Formulations
To resist secondary water treatment chemistries (chloramines, ozone, chlorine dioxide), our elastomer research focus has engineered ultra-high molecular weight crosslinked EPDM seats, lowering chemical swelling degradation and maintaining sealing integrity over 150,000 continuous cycles.
Carbon-Neutral Casting Protocols
In accordance with global ESG mandates, ZFA Valve has transitioned electric induction furnace melting units to utilize 80% recycled ferrous scrap materials combined with automated particulate scrubber filtration, reducing embedded manufacturing carbon footprint by 34% per metric ton.
Frequently Asked Questions: Technical Engineering & Sourcing
Detailed technical clarifications answering questions commonly submitted by project managers, specifying engineers, and global procurement directors.
What mechanical advantages make a double flanged butterfly valve superior to wafer or lug types?
A double flanged butterfly valve features discrete bolted flanges on both ends. This eliminates the lengthy through-bolts of wafer valves, which stretch under thermal variations or high fire loads, causing external flange leaks. Additionally, double flanged valves handle higher pipe stress, thermal pipe deflection, and permit direct downstream line disassembly under full working pressure (dead-end isolation service) without requiring extra blind flanges.
Which international flange drilling patterns are available through your OEM service?
ZFA Valve manufactures double flanged butterfly valves with integrated drilling conforming to ASME B16.5 Class 150/300, ASME B16.47 Series A/B, EN 1092-1 / EN 1092-2 PN10/PN16/PN25/PN40, BS 4504, DIN 2501, AS 2129 Table D/E, JIS B2220 10K/16K, and GOST 12815/33259. Multi-standard universal drilling options are also available upon engineering review.
How do you verify bubble-tight sealing on large diameter double flanged valves?
Every single valve undergoes pressure testing strictly in accordance with EN 12266-1 Rate A and API 598. Shell tests are held at 1.5 times the nominal working pressure, while seat leakage tests are executed bidirectionally at 1.1 times the design pressure. For zero-leakage resilient valves, no measurable droplets or air bubbles are permitted during specified hold durations.
What are the key seat material selection rules for double flanged valves?
Select EPDM for potable water, municipal sewage, cooling towers, and HVAC fluids (-20°C to +120°C). Select NBR (Nitrile) for hydrocarbon fuel lines, industrial lubricating oils, and compressed air systems (-10°C to +82°C). Select PTFE/PFA for concentrated acids, harsh chemicals, and pharmaceutical processes (-20°C to +180°C). For applications exceeding 200°C or high abrasive environments, our Triple Offset Metal-to-Metal seated valve is specified.
What documentation is included in an OEM export order from ZFA Valve?
Our standard export documentation dossier includes the Mill Test Certificate according to EN 10204 Type 3.1, Hydrostatic and Pneumatic Factory Acceptance Test Reports, Paint Coating Thickness Gauge Certificate, Declaration of Conformity with CE/PED, Certificate of Origin, and complete Operation & Maintenance (O&M) manuals.
Engineered Valve Range: High-Performance Products
Explore our extended industrial valves: Triple Offset, Heavy-Duty Gate, Dual-Plate Check, and High-Grade Alloy Butterfly Valves manufactured to client datasheets.
OEM WCB Double Flanged Triple Offset Butterfly Valve
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OEM PN16 5K 10K 150LB Hard Back Seat Wafer Valve
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OEM DI CI SS304 Dual Plate Check Valve
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China Double Flanged Triple Offset Butterfly Valve
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OEM Butt Welded Triple Offset Butterfly Valve
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China DN600 WCB OS&Y Rising Stem Gate Valve
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OEM Brass Bronze Wafer Butterfly Valve
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