Flanged Butterfly Valve – Custom Valve by Leading Foundry

1. Вступ

A Flanged butterfly valve (FBV) is a quarter-turn valve widely recognized as the workhorse of high-pressure and permanent fluid control systems.

Characterized by their integral flanges that bolt directly to pipeline flanges, they provide a rigid, leak-proof, and structurally stable connection,

a critical advantage over wafer-style valves (space-saving but suited for low-pressure duties) and lug-style valves (moderate pressure, often for non-critical service).

Engineered for medium to large-diameter pipelines, flanged butterfly valves combine щільне вимкнення, structural reliability, and ease of maintenance.

В той же час, their versatility makes them indispensable in очищення води, HVAC networks, and general industrial processing, where their компактний дизайн, cost-efficiency, and adaptability across pressure and temperature ranges deliver long-term operational value.

2. What is a Flanged Butterfly Valve?

Core Definition and Working Principle

A flanged butterfly valve (FBV) є a quarter-turn rotary клапан designed for regulating or isolating flow in pipelines.

Its defining feature is the integral flanges, which bolt directly to pipe flanges (per ANSI B16.5 or ISO 7005), creating a rigid, leak-tight, and permanent connection suitable for high-pressure service.

The valve operates on a simple principle:

• Fully Open (0°): The disc lies parallel to flow, minimizing pressure loss (typically 1–3 psi for a 6-inch valve at nominal flow).
• Дросель (10–80°): Partial rotation restricts flow; eccentric disc designs provide more linear flow control than concentric types.
• Fully Closed (90°): The disc presses firmly against the seat, achieving tight shutoff. FBVs are bidirectional, handling forward and reverse flows effectively.

Anatomy of a Flanged Butterfly Valve

A flanged butterfly valve is engineered for durability and precision control, typically comprising six core components:

Flanged vs. Wafer vs. Lug Butterfly Valves

З integral flange design sets FBVs apart from wafer and lug types, offering unique advantages for high-demand applications:

3. Design Variations: Concentric vs. Eccentric Flanged Butterfly Valves

Flanged butterfly valves are classified primarily by disc and stem alignment, a critical factor influencing pressure rating, продуктивність герметизації, torque requirements, and application suitability.

Concentric Flanged Butterfly Valves (Standard Design)

Геометрія: The disc and stem axes align with the valve’s bore center, making the design concentric. During operation, the seat maintains contact across the entire disc surface.

Performance Metrics:

• Pressure Rating: ANSI Class 150–300 (28–70 bar at 20°C)
• Клас герметичності: API 609 Class IV (≤0.01% of nominal flow for liquids)
• Torque Requirement: 60–100 N·m (6-inch valve, EPDM seat)
• Цикл життя: 10,000–20,000 cycles (resilient seat limits lifespan)

Переваги:

• Простий, cost-effective design
• Easy maintenance and seat replacement
• Suitable for moderate temperature and pressure fluids

Обмеження:

• High disc-seat friction reduces efficiency
• Not suitable for gas service or high-pressure applications
• Limited durability under abrasive or high-temperature fluids

Типові програми:

• HVAC chilled water systems
• Municipal water distribution
• Low-pressure, non-critical industrial services

Eccentric Flanged Butterfly Valves (High-Performance Design)

Огляд: Eccentric designs offset the disc or stem, reducing disc-to-seat friction and enhancing sealing performance.

These designs are ideal for високий тиск, high-temperature, and gas applications.

Single Eccentric (Offset Disc) Flanged Butterfly Valve

Дизайн: The disc center is offset from the stem axis, which minimizes contact with the seat during rotation, reducing friction.

Performance Metrics:

• Pressure Rating: ANSI Class 300–600 (70–140 bar)
• Клас герметичності: API 609 Class V (≤0.001% of nominal flow)
• Torque Requirement: 40–70 N·m (6-inch valve, PTFE seat)—~30% lower than concentric valves

Заявки:

• Industrial water treatment
• Low-pressure oil lines
• Applications requiring moderate flow control with improved efficiency

Double Eccentric (Offset Disc + Стовбур) Flanged Butterfly Valve

Дизайн: Both the disc center and stem axis are offset from the bore center. This eliminates disc-seat contact until 80–85% of closure, significantly reducing friction and wear.

Performance Metrics:

• Pressure Rating: Клас ANSI 600 (140 bar at 20°C); up to Class 900 with metal seats
• Клас герметичності: API 609 Клас VI (≤0.00001% of nominal flow) — suitable for gas service, including natural gas pipelines
• Діапазон температури: -29°C to 482°C (metal seats)

Заявки:

• Хімічна обробка
• Нафта & газові трубопроводи
• Steam systems
• High-pressure industrial fluids requiring tight shutoff

Triple Eccentric (Зсув + Tapered Disc) Flanged Butterfly Valve

Дизайн: Adds a third offset by introducing a conical/tapered disc geometry, achieving a metal-to-metal seal without the need for an elastic seat.

This design enables operation under extreme temperatures and pressures.

Performance Metrics:

• Pressure Rating: Клас ANSI 900 (210 bar at 20°C)
• Діапазон температури: -29°C to 650°C (Stellite® or hard metal seats)
• Цикл життя: 50,000–100,000 cycles (metal seat durability)

Заявки:

• Hypersonic vehicle cooling systems
• Power plant superheated steam lines
• Refinery catalytic crackers and petrochemical processing
• Extreme industrial environments requiring zero-leakage and long life

Резюме:

4. Матеріали & Seals of Flanged Butterfly Valve

Виступ, надійність, and longevity of double flanged butterfly valves (FBVs) are strongly influenced by Вибір матеріалу for the body, диск, стовбур, and sealing elements.

Proper materials ensure compatibility with the fluid, резистентність до корозії, high-pressure handling, and suitability for temperature extremes.

Body Materials

The valve body is the primary pressure boundary and must withstand mechanical stress, internal pressure, and environmental corrosion. Common body materials include:

Disc Materials

The disc is directly exposed to flow and often handles абразивний, erosive, or corrosive fluids. Selection is based on механічна міцність, Корозійна стійкість, and sealing compatibility:

• 316 Нержавіюча сталь: Widely used for general-purpose chemical, вода, and steam applications.
• Hastelloy C276: Resistant to oxidizing and reducing chemicals; suitable for aggressive acids.
• Ductile Iron with PTFE Coating: Low-friction, corrosion-resistant option for water and mild chemicals.
• Зоряний®-Clad Discs: High-temperature and high-wear applications, including superheated steam and petrochemicals.

Design Note: The disc may be concentric, eccentric, or triple-offset, with metal or resilient coating to improve sealing and reduce wear.

Stem Materials

The stem transmits torque from the actuator or handwheel to the disc and is exposed to mechanical stress, тиск, and fluid contact. Common materials:

Seat Materials and Seal Types

З seat forms the critical sealing interface with the disc, determining leakage class, torque requirement, і службове життя. Selection depends on Тип рідини, тиск, і температура.

Gaskets and Actuator Interfaces

• Flange Gaskets: Графіт, PTFE, or nitrile gaskets ensure leak-proof flange connections between the valve and pipeline.
• Actuator Seals: O-rings or PTFE bushings prevent fluid leakage along the stem while enabling smooth torque transfer.

5. Виробництво & Foundry Methods of Flanged Butterfly Valves

Виробництво flanged butterfly valves (FBVs) requires high precision, robust materials, and strict adherence to international standards such as API 609, ISO 5752, та ANSI B16.5.

Valves designed for high-pressure and high-performance applications—like oil & газові трубопроводи, хімічні рослини, and power generation—must exhibit розмірна точність, структурна цілісність, and leak-tight performance.

Casting Butterfly Valve Components

Casting is the primary method for shaping valve bodies and discs, allowing complex geometries and cost-effective production. For large valves (typically over 12 дюймів), пісочний кастинг is widely used.

У цьому процесі, molten metal (1450–1550°C) is poured into resin-bonded sand molds.

Sand casting offers tolerances around ±0.5 mm, making it suitable for carbon steel or ductile iron valves used in municipal water or low-pressure industrial pipelines.

For small-to-medium valves (2–12 inches) requiring high dimensional precision and corrosion resistance, інвестиційне кастинг (lost wax method) is employed. Wax patterns are coated with ceramic shells, melted out, and replaced with molten metal.

This method achieves tight tolerances (±0,1 мм) і гладкі поверхні, enabling precise features such as double eccentric disc hubs.
Investment casting is ideal for 316L stainless steel, Хастеллой, or other corrosion-resistant alloys.

Кування: High-Strength Components

Forging is the preferred method for critical, high-pressure components such as bodies, фланці, and stems, because it produces superior grain structure and higher tensile strength.

Heated metal (1100–1200°C) is shaped under hydraulic presses or dies, resulting in 20–30% stronger parts than equivalent castings.

Forged components are typically used in ANSI Class 600 or higher valves for oil & газові трубопроводи, електростанції, and other demanding industrial applications.

Forging methods include open-die forging for large custom parts, closed-die forging for medium-sized components with precise dimensions, and upset forging to reinforce critical junctions like disc hubs.

Обробка: Precision Finishing

After casting or forging, Обробка ЧПУ ensures high dimensional accuracy, поверхнева обробка, and proper alignment:

• Flange faces are milled to achieve flatness within 0.1 mm and bolt hole alignment per ANSI B16.5 standards, ensuring leak-free connections.
• Seat bores are honed or machined to Ra 1.6–3.2 μm to allow proper seat bonding and effective sealing.
• Discs and hubs, especially eccentric designs, are finished with 5-axis CNC milling to maintain flatness within 0.05 mm for tight shutoff.
• Stems and bearings are turned and milled with precision to guarantee smooth rotation and correct torque transfer.

Термічна обробка: Mechanical and Corrosion Properties

Heat treatment improves strength, твердість, and corrosion resistance depending on the material used:

• Вуглецева сталь (WCB): Quenched at 850°C and tempered at 650°C to achieve tensile strength ≥485 MPa.
• 316L нержавіюча сталь: Solution-annealed at 1050–1100°C followed by water quenching to restore corrosion resistance and homogenize microstructure.
• Дуплекс 2205: Solution-annealed at 1020–1080°C to achieve a balanced austenite/ferrite ratio (50:50), optimizing both strength and corrosion resistance.

Поверхнева обробка: Довговічність & Корозійна стійкість

Surface finishing ensures durability in harsh environments:

• Пасивація for 316L stainless steel enhances the natural chromium oxide layer, improving corrosion resistance by up to 20%.
• Епоксидні покриття of 100–150 μm protect carbon steel bodies in oil & gas pipelines from soil and atmospheric corrosion.
• Електропалізація is used in sanitary applications (харчування, напій, фармацевтичні препарати) to achieve Ra ≤0.8 μm, eliminating microscopic crevices and bacterial dead zones.

Складання & Забезпечення якості

After machining and surface treatment, valves undergo assembly and rigorous quality control:

• Seat and disc integration: Seats are bonded or pressed, and eccentric discs are carefully aligned for precise shutoff.
• Stem installation: Підшипники, упаковка, and O-rings are fitted, and torque is verified.
• Hydrostatic or pneumatic testing: Confirms leak-tight performance under design pressure.
• Неруйнівне тестування (NDT): Methods such as X-ray, ультразвуковий, or dye penetrant inspections detect internal defects.
• Actuator calibration: Посібник, електричний, пневматичний, or hydraulic actuators are tested for torque and stroke accuracy.

6. Номінальний тиск, Sizes & Стандарти

Flanged butterfly valves (FBVs) are designed for reliability across a wide range of pressures, розміри, and industrial standards.

Proper selection ensures safety, довгострокова продуктивність, and compatibility with pipeline systems.

Номінальний тиск

Standard Sizes

Face-to-Face Dimensions: Usually conform to ISO 5752 Серія 10 or API 609 for easy interchangeability.

Key Standards & Certifications

7. Actuation & Control Systems

Flanged butterfly valves are quarter-turn devices requiring actuators capable of 90° rotation.

Actuator selection depends on valve size, torque requirement, Тип рідини, and control sophistication.

Common Actuator Types and Specifications

Key Accessories for Enhanced Control

• Positioners: Provide precise modulating control (±0.5% accuracy), crucial for applications like HVAC chilled water, хімічне дозування, or industrial process lines.
• Torque Switches: Protect the disc and seat from over-torquing, preventing premature wear or damage.
• Limit Switches: Deliver open/closed position feedback to SCADA or DCS systems for remote monitoring and automated safety protocols.
• Solenoid Valves & Air Filters (for pneumatic actuators): Ensure rapid, reliable actuation while protecting internal actuator components from contaminants.

8. Flanged End Geometry & Interface

З flanged end design is the defining characteristic of butterfly flange valves, ensuring a rigid, secure, and leak-tight connection to pipeline systems.

The geometry is standardized globally to allow full interchangeability across manufacturers.

Flange Standards & Compatibility

Flanged butterfly valves are machined to match pipeline flanges in розміри, bolt-hole patterns, and pressure ratings. The most common standards include:

Dimensional Geometry

The flanged end geometry typically includes:

• Raised Face (РФ): Standard sealing surface, 2–6 mm raised area around the bore, ensures even gasket compression.
• Flat Face (FF): Used with cast iron pipelines to avoid overstressing flanges.
• Ring-Type Joint (RTJ): Machined grooves for metal gaskets, suited for high-pressure/high-temperature services (до 210 бар, 650° C).

9. Industrial Applications of Flanged Butterfly Valves

Flanged butterfly valves are універсальний, high-performance quarter-turn valves widely used across industrial sectors due to their reliability, компактний дизайн, and adaptability to a broad range of pressures, температура, and fluids.

Очищення води та стічних вод

• Застосування: Flow isolation, хімічне дозування, and backwashing systems.
• Переваги: Tight shutoff, low-pressure drop, corrosion-resistant seats for treated water or chemical additives.
• Приклад: Municipal water distribution networks employ butterfly flange valves for diameters exceeding 12 дюймів, ensuring maintenance-friendly operation.

Нафтогазова промисловість

• Застосування: Crude oil pipelines, refined products, gas distribution, and offshore platforms.
• Переваги: High-pressure tolerance (Клас ANSI 600 and above), bidirectional flow capability, compatibility with hydrocarbons and corrosive fluids.
• Приклад: Double or triple eccentric flanged butterfly valves control oil and gas pipelines where minimal leakage and high reliability are mandatory.

Генерація живлення

• Застосування: Пара, охолоджуюча вода, and feedwater systems in thermal and nuclear plants.
• Переваги: Високотемпературна толерантність, tight sealing for steam lines, rapid quarter-turn actuation for safety.
• Приклад: Triple eccentric butterfly flange valves handle superheated steam at 482°C in power plant feedwater lines.

Chemical and Petrochemical Processing

• Застосування: Aggressive chemicals, кислоти, and high-temperature processes.
• Переваги: Матеріальна універсальність (316Л, Хастеллой, Дуплекс 2205), precise throttling, minimal friction for controlled flow.
• Приклад: Eccentric flanged butterfly valves with metal seats prevent leakage in sulfuric acid or caustic soda lines.

Нагрівання, Вентиляція, and Air Conditioning (ОВК) and Industrial Chilled/Hot Water Systems

• Застосування: Flow regulation in chilled water loops, cooling towers, and heating systems.
• Переваги: Економічний, легкий, low-pressure rating suitable for non-critical applications, easy maintenance.
• Приклад: Concentric butterfly flange valves regulate building-wide chilled water distribution efficiently.

Їжа, Beverage, and Pharmaceutical Industries

• Застосування: Sanitary processing lines, CIP (Clean-in-Place) системи.
• Переваги: Electropolished stainless steel, FDA-approved seats, smooth surfaces eliminate bacterial growth zones.
• Приклад: Flanged butterfly valves with EPDM or PTFE seals ensure hygienic flow control in beverage bottling plants.

Mining and Slurry Handling

• Застосування: Tailings pipelines, slurry transport, and water control.
• Переваги: Robust construction, abrasion-resistant discs and seats, compatibility with viscous or particle-laden fluids.
• Приклад: Carbon steel double flanged butterfly valve with hardened seats handle mineral slurries without rapid wear.

10. Порівняння з іншими клапанами

11. Висновок

З flanged butterfly valve is a versatile and cost-efficient solution for fluid control, offering a balance of compact design, high flow capacity, and reliable sealing.

Its adaptability to different materials, pressure classes, and actuation methods makes it indispensable across industries ranging from municipal water to petrochemicals.

For engineers and procurement teams, selecting the right FBV involves evaluating media compatibility, умови експлуатації, показники ефективності, and lifecycle costs.

With ongoing advances in materials and automation, flanged butterfly valves will remain a cornerstone of industrial flow control.

Custom Valves from DEZE Foundry

From water treatment plants and HVAC systems to oil & газові трубопроводи, хімічні реактори, and power generation networks, flanged butterfly valves deliver precise flow regulation and tight shutoff under demanding conditions.

Their quarter-turn operation, compact structure, and wide material options enable customization for specific fluids, тиск, and temperatures.

As a professional valve foundry and supplier, we provide custom-engineered flanged butterfly valves and precision-cast components, meeting international standards (API, ISO, Ансі) while ensuring cost-effective performance.

Whether your project requires large-diameter high-pressure service, Корозійні стійкі сплави, or optimized designs for maintenance efficiency, our manufacturing expertise ensures reliable solutions tailored to your industry.

Зв’яжіться з нами зараз!

Поширені запитання

Can flanged butterfly valves handle high-pressure gas service?

Yes—double/triple eccentric flanged valves with metal seats (API 609 Class VI leakage) and ANSI Class 300–900 ratings are suitable for high-pressure gas (Напр., природний газ, азот).

Ensure compliance with ISO 15848-1 Class AH for low fugitive emissions.

What is the maximum size of a flanged butterfly valve?

Most manufacturers offer flanged butterfly valves up to 48 дюймів (1200 мм) in diameter, suitable for large water treatment plants and oil & газові трубопроводи.

Custom designs can reach 60 дюймів (1500 мм) for specialized applications.

How do I prevent flange gasket leakage?

Use gaskets compatible with fluid/temperature (Напр., graphite for steam, PTFE for chemicals); tighten bolts in a crisscross pattern (per ASME PCC-1) to uniform torque (Напр., 70 N·m for 6-inch ANSI 300 фланці); replace gaskets annually.

Are flanged butterfly valves suitable for sanitary service?

Yes—select 316L bodies with electropolished surfaces (Ra ≤0,8 мкм), PTFE seats, and tri-clamp flanges (3-A/EHEDG compliant).

These valves are used in dairy, напій, and pharmaceutical manufacturing.

What is the difference between ANSI Class 300 і 600 flanged valves?

Клас ANSI 300 valves handle up to 70 бар (20° C), Поки клас 600 handles up to 140 бар (20° C).

Клас 600 valves have thicker bodies (20–30 mm vs. 15–20 mm for Class 300) and stronger flanges, making them suitable for high-pressure applications like refineries and offshore pipelines.