1. Introductio
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 (moderatus, often for non-critical service).
Engineered for medium to large-diameter pipelines, flanged butterfly valves combine stricta shutoff, structural reliability, and ease of maintenance.
Simul, their versatility makes them indispensable in AQUA, HVAC networks, and general industrial processing, where their compact design, 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) est quarter-turn rotary valvae 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 (0Die): The disc lies parallel to flow, minimizing pressure loss (typically 1–3 psi for a 6-inch valve at nominal flow).
- Throttling (10–80°): Partial rotation restricts flow; eccentric disc designs provide more linear flow control than concentric types.
- Fully Closed (90Die): 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:
| Component | Design Features | Primary Role |
| Corpus (with Flanges) | Cast/forged with integral flanges; bolt holes align to pipeline flanges. | Provides pressure boundary and permanent mounting. |
| Pervideo | Circular plate (flat or eccentric profile). | Rotates to open/close or throttle flow. |
| Caule (Shaft) | Solid rod, sealed by packing/O-rings. | Transmits torque from actuator to disc. |
| Sessio | Laevis (EPDM/PTFE) or metal (Stellite, Ss). | Ensures leak-tight sealing against the disc. |
| Flange Gasket | Compressible sealing material between flanges. | Prevents external leakage. |
| Actuator | Manual, electrica, pneumatic, or hydraulic. | Provides quarter-turn control for isolation or modulation. |
Flanged vs. Wafer vs. Lug Butterfly Valves
In integral flange design sets FBVs apart from wafer and lug types, offering unique advantages for high-demand applications:
| Pluma | Flags papilio valvae | Wafer papfus valvae | Lug Butterfly Valve |
| Mounting | Bolted via integral flanges | Clamped between flanges | Bolted via threaded body lugs |
| Pressura Rating | ANSI 150–900 (28–210 bar) | ANSI 150–300 (28–70 bar) | ANSI 150–600 (28–140 bar) |
| Pondus (6-inch, Ss) | ~12 kg | ~5.6 kg | ~ VIII kg |
| Pipeline Disassembly | Requires unbolting flanges | Requires removing flange pair | Valve-only removal possible |
| Relativum Cost | Superior (1.5×) | Inferior (0.7×) | Medium (1.0×) |
| Optimum | Summus, permanent service (oleum, Gas, vapor, chemicals) | Low-pressure, compact systems | Medium-pressure, flexible maintenance needs |
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, Signatio perficientur, torque requirements, Et application idoneitatem.
Concentric Flanged Butterfly Valves (Standard Design)
GEOMETRY: 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:
- Pressura Rating: ANSI Class 150–300 (28–70 bar at 20°C)
- Ultrices Classis: API 609 Class IV (≤0.01% of nominal flow for liquids)
- Torque Requirement: 60–100 N·m (6-inch valve, EPDM seat)
- Cycle Life: 10,000–20,000 cycles (resilient seat limits lifespan)
Commoda:
- Simplex, cost-effective design
- Easy maintenance and seat replacement
- Suitable for moderate temperature and pressure fluids
Limitations:
- High disc-seat friction reduces efficiency
- Not suitable for gas service or high-pressure applications
- Limited durability under abrasive or high-temperature fluids
Typical applications:
- HVAC chilled water systems
- Municipal water distribution
- Low-pressure, non-critical industrial services
Eccentric Flanged Butterfly Valves (High-Performance Design)
Overview: Eccentric designs offset the disc or stem, reducing disc-to-seat friction and enhancing sealing performance.
These designs are ideal for summus pressura, caligo, and gas applications.
Single Eccentric (Offset Disc) Flags papilio valvae
Consilio: The disc center is offset from the stem axis, which minimizes contact with the seat during rotation, reducing friction.

Performance Metrics:
- Pressura Rating: ANSI Class 300–600 (70–140 bar)
- Ultrices Classis: API 609 Genus V (≤0.001% of nominal flow)
- Torque Requirement: 40–70 N·m (6-inch valve, PTFE seat)—~30% lower than concentric valves
Applications:
- Industrial water treatment
- Low-pressure oil lines
- Applications requiring moderate flow control with improved efficiency
Double Eccentric (Offset Disc + Caule) Flags papilio valvae
Consilio: 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:
- Pressura Rating: Ansi genus 600 (140 bar at 20°C); ad genus 900 with metal seats
- Ultrices Classis: API 609 Genus VI (≤0.00001% of nominal flow) — suitable for gas service, including natural gas pipelines
- Temperature range: -29°C ad 482°C (metallum sedes)
Applications:
- Eget processus
- Oleum & Gas Pipelines
- Steam systems
- High-pressure industrial fluids requiring tight shutoff
Triple Eccentric (Offset + Tapered Disc) Flags papilio valvae
Consilio: 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:
- Pressura Rating: Ansi genus 900 (210 bar at 20°C)
- Temperature range: -29C ad DCL ° C (Stellite® or hard metal seats)
- Cycle Life: 50,000–100,000 cycles (metal seat durability)
Applications:
- Hypersonic vehicle cooling systems
- Power plant superheated steam lines
- Refinery catalytic crackers and petrochemical processing
- Extreme industrial environments requiring zero-leakage and long life
Summary:
| Pluma | Concentricis | Single Eccentric | Double Eccentric | Triple Eccentric |
| Disc-Stem Alignment | Centerline | Disc offset | Pervideo + stem offset | Pervideo + stem + conical offset |
| Pressura Rating | 28–70 bar | 70–140 bar | 140–210 bar | 210 sera |
| Ultrices Classis | IV | V | VI | VI (metallum) |
| Torque Requirement | Moderor | Lower than concentric | Superior | Altum (requires actuator) |
| Temperature range | - | Moderor | -29°C ad 482°C | -29C ad DCL ° C |
| Typical usu | Low-pressure water/HVAC | Moderate industrial fluids | High-pressure fluids/gases | Extreme industrial/petrochemical |
4. Materies & Seals of Flanged Butterfly Valve
Ad perficientur, reliability, and longevity of double flanged butterfly valves (FBVs) are strongly influenced by Material Electio for the body, pervideo, stem, and sealing elements.
Proper materials ensure compatibility with the fluid, resistentia ad corrosio, 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:
| Materia | Features | Typical applications |
| Carbon Steel (A216 WCB) | Excelsum, Moderare corrosio resistentia, ECFECTUS | Aquam, vapor, low-corrosive chemicals |
| Immaculatam ferro (316/316L, A351 CF8M) | Optimum corrosio resistentia, hygienic, moderate high-temperature resistance | Eget processus, cibus & potum, marine environments |
| Ferrum (En-gjs, 400-15, ASTM A536) | Vires, ECFECTUS, corrosion-resistant when coated | Water distribution, LEPIDUS, Hvac |
| Alloy Steel (C276 Critica, Duplex 2205) | Superior chemical and temperature resistance | Petrochemical, acida, aggressive industrial fluids |
Disc Materials
The disc is directly exposed to flow and often handles abrasive, erosive, or corrosive fluids. Selection is based on Mechanica fortitudinem, corrosio resistentia, and sealing compatibility:
- 316 Immaculatam ferro: Widely used for general-purpose chemical, aquam, and steam applications.
- C276 Critica: 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.
- Stellite®-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, pressura, and fluid contact. Common materials:
| Materia | Features | Applications |
| 416 Immaculatam ferro | Excelsum, Bonum corrosio resistentia, ECFECTUS | Aquam, Hvac, general industry |
| 316/316L immaculatam ferro | Optimum corrosio resistentia, moderate high-temperature resistance | Proiectus, marinus, cibus & potum |
| C276 Critica / Duplex Steel | Extreme corrosion and temperature resistance | infestantibus chemicals, high-pressure petrochemical |
Seat Materials and Seal Types
In seat forms the critical sealing interface with the disc, determining leakage class, torque requirement, et servitium vitae. Selection depends on fluid type, pressura, et temperatus.
| Sedes type | Materia | Ultrices Classis | Temperature range | Nota |
| Resilient Seat | EPDM, NRB, FKM, Ptfe | API 609 Class IV-V | -50C ad CC ° C | Excellent sealing for liquids; low torque; not for high-temp steam |
| Metal Seat | Immaculatam ferro, Stellite® | API 609 Genus VI | -29C ad DCL ° C | Princeps vetustatem; suitable for gases, summus pressura, and high-temperature applications |
| Ptfe-Lined | Pure PTFE or filled PTFE | API 609 Genus V | -50C ad CC ° C | Chemically repugnant; frictio; may creep under high pressure |
| Elastomer + Metal Hybrid | EPDM/Metal or PTFE/Metal | API 609 Class V–VI | -29°C ad 482°C | Combines leak-tightness with wear resistance; common in double-eccentric designs |
Gaskets and Actuator Interfaces
- Flange Gaskets: Graphite, 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. Vestibulum & Foundry Methods of Flanged Butterfly Valves
Productio flanged butterfly valves (FBVs) requires high precision, robust materials, and strict adherence to international standards such as API 609, Iso 5752, and ANSI B16.5.
Valves designed for high-pressure and high-performance applications—like oil & Gas Pipelines, Plantae, and power generation—must exhibit Dimensional accurate, structural integritas, 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. Nam magnae valvulae (typically over 12 pollices), harenae mittentem is widely used.
Hoc, 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, Investment casting (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 mm) and smooth surfaces, enabling precise features such as double eccentric disc hubs.
Investment casting is ideal for 316L stainless steel, CAMPESCO, or other corrosion-resistant alloys.
Fuscus: High-Strength Components
Forging is the preferred method for critica, high-pressure components such as bodies, flanges, 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 & Gas Pipelines, Power plantae, 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.
Machining: Precision Finishing
After casting or forging, Cnc machining ensures high dimensional accuracy, superficiem metam, 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.
Calor: Mechanical and Corrosion Properties
Heat treatment improves strength, durities, and corrosion resistance depending on the material used:
- Carbon chalybe (WCB): Quenched at 850°C and tempered at 650°C to achieve tensile strength ≥485 MPa.
- 316L immaculatam ferro: Solution-annealed at 1050–1100°C followed by water quenching to restore corrosion resistance and homogenize microstructure.
- Duplex 2205: Solution-annealed at 1020–1080°C to achieve a balanced austenite/ferrite ratio (50:50), optimizing both strength and corrosion resistance.
Superficies Curatio: Longevitas & Corrosio resistentia
Surface finishing ensures durability in harsh environments:
- POSTIVATIO for 316L stainless steel enhances the natural chromium oxide layer, improving corrosion resistance by up to 20%.
- Epoxy coatings of 100–150 μm protect carbon steel bodies in oil & gas pipelines from soil and atmospheric corrosion.
- Electropolishing is used in sanitary applications (cibus, potum, Pharmaceuticals) to achieve Ra ≤0.8 μm, eliminating microscopic crevices and bacterial dead zones.
Conventus & Qualitas fide
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: Gestus, stipare, and O-rings are fitted, and torque is verified.
- Hydrostatic or pneumatic testing: Confirms leak-tight performance under design pressure.
- Non-perniciosius testis (NDT): Methods such as X-ray, Ultrasonic, or dye penetrant inspections detect internal defects.
- Actuator calibration: Manual, electrica, pneumatic, or hydraulic actuators are tested for torque and stroke accuracy.
6. Pressure Ratings, Sizes & Signa
Flanged butterfly valves (FBVs) are designed for reliability across a wide range of pressures, sizes, and industrial standards.
Proper selection ensures safety, long-term performance, and compatibility with pipeline systems.
Pressure Ratings
| Pressure Class | Max Working Pressure (20N ° C) | Typical Seat Material | Nota / Applications |
| Ansi genus 150 | 19 sera | EPDM, Ptfe | Low-pressure water and HVAC systems |
| Ansi genus 300 | 51 sera | EPDM, Ptfe | Municipal water, low-pressure industrial pipelines |
| Ansi genus 600 | 102 sera | Metallum, Composite | Oleum & Gas, eget processus |
| Ansi genus 900 | 155 sera | Metallum | Summus pressura vapor, conflatorio, extreme temperature service |
Standard Sizes
| Nominal Diameter (Dn) | Inch Size | Typical applications | Nota |
| DN 50–150 | 2–6 | Laboratory systems, Hvac, small water pipelines | Conpactum, facile install |
| DN 200–600 | 8–24 | Municipal water, eget processus, industrial pipelines | Standard industrial range |
| DN 700–1200 | 28–48 | Large-scale oil & Gas, LIBELLUS, Power plantae | High-flow, high-pressure service |
| DN 1400–2000+ | 56–80+ | Heavy industrial, refineries, hydroelectric | Custom manufacturing often required |
Face-to-Face Dimensions: Usually conform to ISO 5752 Series 10 or API 609 for easy interchangeability.
Key Standards & Testimonia
| Vexillum / Certification | Scopus | Applicatio / Relevantia |
| API 609 | Consilio & testing of industrial butterfly valves | Generalis industriae ministerium |
| Iso 5752 | Faciem ad faciem & flange dimensions | Ensures interchangeability |
| Asme B16.34 | Pressure-temperature ratings for metallic valves | Structural integrity & salus |
| MSS SP-67 | inspectionem & flow coefficient standardization | Accurate flow control |
| ASTM A216 / A351 | Carbon chalybe & immaculatam ferro castings | Material quality for pressure service |
| ASME B16.5 | Flange dimensions & bolt patterns | Compatibility with pipelines |
| API 598 / Iso 5208 | Crusta & seat leakage testing | Ensures leak-tight performance |
| Nace Mr0175 / Iso 15156 | Corrosion resistance for sour oil & gas service | Long-term reliability in aggressive environments |
| PED 2014/68/EU | Pressure equipment compliance (Europa) | Legal & safety compliance for EU installations |
7. Actum & Control Systems
Flanged butterfly valves are quarter-turn devices requiring actuators capable of 90° rotation.
Actuator selection depends on valve size, torque requirement, fluid type, and control sophistication.

Common Actuator Types and Specifications
| Actuator Type | Typical Valve Size (Inches) | Torque Range (N·m) | Potestas / Energy Source | Responsio Tempus | Control Capability | Fail-Safe Option |
| Manual Handwheel | 2–6 | 10-50 | Human operation | <5 s | On/Off | N / est |
| Gear Operator | 8–24 | 80-300 | Manual with mechanical advantage | 30–60 s | On/Off | N / est |
| Electric Actuator | 2-36 | 50-1000 | AC 110/220V, DC 24V | 5-30 s | Modulating /On/Off | Battery backup |
| Pneumatic Actuator | 2-36 | 50-500 | 6–8 bar compressed air | 0.5–5 s | Modulating /On/Off | Spring return |
| Hydraulic Actuator | 12–48 | 500-2000 | 10–30 MPa hydraulic fluid | 1–10 s | On/Off | Pressure reserve |
Key Accessories for Enhanced Control
- Positioners: Provide precise modulating control (±0.5% accuracy), crucial for applications like HVAC chilled water, chemical dosing, 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
In 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 dimensiones, bolt-hole patterns, et pressura ratings. The most common standards include:
| Vexillum | Regio / Applicatio | Pressure Classes | Nota |
| ASME B16.5 | North America / ILLICUS | Class 150–900 | Widely used in oil, Gas, proiectus, and power sectors |
| Iso 7005 | Internecivus | PN 6–PN 160 | Metric system equivalent to ASME |
| In 1092-1 | Europa | PN 10–PN 160 | Used across EU pipelines and process industries |
| JIS B2220 | Iaponia / Asia | 5K–40K | Common in Asian industrial networks |
Dimensional Geometry
The flanged end geometry typically includes:
- Raised Face (Rf): 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 (ad 210 sera, 650N ° C).
| Geometry Type | Pressura range | Typical applications |
| Flat Face (FF) | Humilis (PN 6–PN 16) | Water distribution, Hvac |
| Raised Face (Rf) | Medium (PN 10–PN 100) | Oleum & Gas, Plantae |
| RTJ | Altum (PN 100–PN 160, Class 600–900) | Offshore, refining, vapor |
9. Industrial Applications of Flanged Butterfly Valves
Flanged butterfly valves are versabilis, high-performance quarter-turn valves widely used across industrial sectors due to their reliability, compact design, and adaptability to a broad range of pressures, temperaturis, and fluids.
Aqua et wastewater Curatio
- Applicatio: Flow isolation, chemical dosing, and backwashing systems.
- Commoda: stricta shutoff, low-pressure drop, corrosion-resistant seats for treated water or chemical additives.
- Exemplar: Municipal water distribution networks employ butterfly flange valves for diameters exceeding 12 pollices, ensuring maintenance-friendly operation.
Oleum et Gas industria
- Applicatio: Crude oil pipelines, refined products, gas distribution, and offshore platforms.
- Commoda: High-pressure tolerance (Ansi genus 600 et supra), bidirectional flow capability, compatibility with hydrocarbons and corrosive fluids.
- Exemplar: Double or triple eccentric flanged butterfly valves control oil and gas pipelines where minimal leakage and high reliability are mandatory.
Generatio
- Applicatio: Vapor, refrigerationem aquae, and feedwater systems in thermal and nuclear plants.
- Commoda: High-temperature tolerance, tight sealing for steam lines, rapid quarter-turn actuation for safety.
- Exemplar: Triple eccentric butterfly flange valves handle superheated steam at 482°C in power plant feedwater lines.
Chemical and Petrochemical Processing
- Applicatio: infestantibus chemicals, acida, and high-temperature processes.
- Commoda: Material versatility (316L, CAMPESCO, Duplex 2205), CIRCUMSPECTATIO, minimal friction for controlled flow.
- Exemplar: Eccentric flanged butterfly valves with metal seats prevent leakage in sulfuric acid or caustic soda lines.
Calefactio, Evacuatio, et aer condiciones (Hvac) and Industrial Chilled/Hot Water Systems
- Applicatio: Flow regulation in chilled water loops, cooling towers, and heating systems.
- Commoda: Sumptus efficens, LIBRICUS, low-pressure rating suitable for non-critical applications, easy maintenance.
- Exemplar: Concentric butterfly flange valves regulate building-wide chilled water distribution efficiently.
Cibus, Potus, and Pharmaceutical Industries
- Applicatio: Sanitary processing lines, CIP (Clean-in-Place) systems.
- Commoda: Electropolished stainless steel, FDA-approved seats, smooth surfaces eliminate bacterial growth zones.
- Exemplar: Flanged butterfly valves with EPDM or PTFE seals ensure hygienic flow control in beverage bottling plants.
Mining and Slurry Handling
- Applicatio: Tailings pipelines, slurry onerariis, and water control.
- Commoda: Robust construction, abrasion-resistant discs and seats, compatibility with viscous or particle-laden fluids.
- Exemplar: Carbon steel double flanged butterfly valve with hardened seats handle mineral slurries without rapid wear.
10. Collatio cum aliis valvulae
| Pluma / Type CYMBALON | Flags papilio valvae | Porta CYMBALON | Globe valvae | Pila valvae | Plug Valve |
| Operatio | Quarter-turn (90Die) | Linear (rising/non-rising stem) | Linear (throttle/open/close) | Quarter-turn (90Die) | Quarter-turn (90Die) |
| Shutoff capability | Moderate to tight (Class IV–VI) | Praeclarus (metallum-ut-metallum) | Praeclarus (metallum-ut-metallum) | Praeclarus (bulla-stricta) | Bonum optimum |
| Pressura Rating | ANSI Class 150–900 (28–210 bar) | ANSI Class 150–2500 | ANSI Class 150–600 | ANSI Class 150–900 | ANSI Class 150–600 |
| Fluxus / Throttling | Moderate precision; eccentric design improves | Pauper; mainly on/off | Praeclarus; designed for throttling | Limited; mostly on/off | Moderor |
| Magnitudo dolor | 2–48 inches (DN50–1200) | 0.5–120 inches | 0.5–48 inches | 0.5–48 inches | 0.5–24 inches |
| Pondus | Light to moderate | Gravis | Moderor | Light | Moderor |
| Sustentationem | Securus (flanged connection; seat replacement) | Difficilis (disassembly, heavy components) | Moderor (stipare derivantur, sede lapsum) | Securus (ball removal, minimal parts) | Moderor |
| Cost | Moderor | Altum | Altum | Altum | Moderor |
| Installation Space | Conpactum | Large | Moderor | Conpactum | Moderor |
| PROPRESSUS | Aquam, LEPIDUS, Hvac, proiectus, oleum & Gas Pipelines | High-pressure isolation | Flow regulation and throttling | On/off control, corrosive fluids, summus pressura | Slurries, oleum, Gas, corrosive liquids |
| Bidirectional fluxus | Sic | Sic | Usually | Sic | Usually |
| Responsio Tempus | Ieiunium (quarter-turn) | Tardus (linear travel) | Tardus | Ieiunium (quarter-turn) | Ieiunium (quarter-turn) |
11. Conclusio
In 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, pressura 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, operating conditionibus, performance metrics, et 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 & Gas Pipelines, eget reactors, 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, pressuris, et temperaturis.

As a professional valve foundry and supplier, we provide custom-engineered flanged butterfly valves and precision-cast components, meeting international standards (API, Iso, ANSI) while ensuring cost-effective performance.
Whether your project requires large-diameter high-pressure service, corrosion-resistant alloys, or optimized designs for maintenance efficiency, our manufacturing expertise ensures reliable solutions tailored to your industry.
Contact Us now!
FAQs
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 (E.g., natural gas, nitrogen).
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 pollices (1200 mm) diametro, suitable for large water treatment plants and oil & Gas Pipelines.
Custom designs can reach 60 pollices (1500 mm) for specialized applications.
How do I prevent flange gasket leakage?
Use gaskets compatible with fluid/temperature (E.g., graphite for steam, PTFE for chemicals); tighten bolts in a crisscross pattern (per ASME PCC-1) to uniform torque (E.g., 70 N·m for 6-inch ANSI 300 flanges); replace gaskets annually.
Are flanged butterfly valves suitable for sanitary service?
Yes—select 316L bodies with electropolished surfaces (Ra ≤0.8 μm), PTFE seats, and tri-clamp flanges (3-A/EHEDG compliant).
These valves are used in dairy, potum, and pharmaceutical manufacturing.
What is the difference between ANSI Class 300 et 600 flanged valves?
Ansi genus 300 valves handle up to 70 sera (20N ° C), while Class 600 handles up to 140 sera (20N ° C).
Genus 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.



