What is a Flanged Butterfly Valve?
A Flanged Butterfly Valve is a quarter-turn flow control device that features integral flanged ends on both sides of the valve body, allowing it to be bolted directly between pipe flanges or directly to mating flanges on equipment. Unlike wafer-style butterfly valves which are clamped between flanges, flanged butterfly valves have built-in flanges with bolt holes, providing a more secure, rigid connection — especially important in larger diameters and higher-pressure applications.
The valve operates by rotating a disc (the “butterfly”) 90 degrees from fully open to fully closed. When open, the disc is parallel to the flow direction, creating minimal pressure drop. When closed, the disc presses against a resilient seat to achieve a bubble-tight seal.
The flanged design offers superior mechanical strength, easier alignment during installation, and the ability to be removed from a pipeline without disturbing adjacent pipes — a significant advantage for maintenance in large water systems.
At WEIZIDOM, our Flanged Butterfly Valves are manufactured with strict quality control and comply with multiple international standards, making them a trusted choice for water systems in over 108 countries worldwide.
Technical Specifications
Design Standard: GB/T12238, API 609, JIS B2032, DIN 3354, BS 5155, DIN EN593.
Diameter range: DN50~2200
Pressure range: PN6/PN10/PN16/CLASS150/5K/10K
Medium: Water, Oil, Gas
Material: Valve body & disc: DI, WCB, CF8, CF8M, CF3M; Valve seat: EPDM, NBR, PTFE, VITON;
Application fields: Water supply and drainage, sewage treatment, chemical industry, power generation, desulfurization systems, shipbuilding, etc.
Main Function in Water Systems
In water systems, the Flanged Butterfly Valve serves as a robust, reliable, and easy-to-maintain flow control device for medium to large diameter pipelines.
Its primary functions include:
|
Function |
Description |
|
Flow Isolation |
Provides complete shut-off for pipeline sections, allowing safe maintenance, repair, or replacement of downstream components. |
|
Flow Regulation (Throttling) |
Excellent for modulating flow — used in pressure reducing stations, flow balancing, and process control applications. |
|
Pump Station Control |
Installed at pump suction and discharge lines to start, stop, or regulate flow entering or leaving pumping stations. |
|
Tank & Reservoir Isolation |
Mounted on tank inlet/outlet pipes to isolate storage vessels for cleaning, inspection, or repair. |
|
Emergency Shut-Off |
Quarter-turn operation enables rapid closure in emergency situations, protecting equipment and preventing backflow. |
|
Distribution Network Sectioning |
Divides large water distribution networks into manageable zones for pressure management and leak detection. |
|
Industrial Process Control |
Used in cooling water circuits, chemical dosing lines, and wastewater treatment processes for precise flow adjustment. |
Typical applications include:
✔ Water supply and drainage networks
✔ Sewage treatment plants
✔ Chemical industry water circuits
✔ Power generation cooling systems
✔ Flue gas desulfurization (FGD) systems
✔ Shipbuilding and marine water systems
✔ HVAC water loops
✔ Irrigation and industrial process lines
✔ Large-diameter municipal water mains (up to DN2200)
Key Features & Advantages
WEIZIDOM’s Flanged Butterfly Valve is engineered for large-scale water systems, demanding industrial environments, and long-term reliability.
Below are its standout features:
|
Feature |
Advantage |
|
Integral Flanged Ends |
Built-in flanges with drilled bolt holes provide a rigid, secure connection to pipeline flanges — eliminates the need for additional flange adapters and allows valve removal without disturbing adjacent pipes. |
|
Wide Diameter Range |
Available from DN50 to DN2200, covering everything from branch lines to the largest water transmission mains. |
|
Multi-Standard Compliance |
Designed to meet GB/T12238, API 609, JIS B2032, DIN 3354, BS 5155, and DIN EN593 — suitable for projects worldwide. |
|
Flexible Pressure Ratings |
Supports PN6, PN10, PN16, CLASS 150, 5K, and 10K — compatible with low to standard pressure water systems globally. |
|
Multiple Material Options |
Valve body and disc available in Ductile Iron (DI), WCB (carbon steel), CF8 (SS304), CF8M (SS316), CF3M (SS316L) — choose based on water quality, corrosion resistance, and budget. |
|
Versatile Seat Materials |
Seat options include EPDM (general water), NBR (oil/gas), PTFE (chemical resistance), VITON (high temperature/aggressive chemicals) — tailored to your specific medium. |
|
Bubble-Tight Shut-Off |
Resilient seat design provides zero leakage when closed, meeting or exceeding ISO 5208 rate A requirements. |
|
Low Torque Operation |
Optimized disc geometry and low-friction seat materials reduce operating torque, enabling manual or actuated operation with smaller, lower-cost actuators. |
|
Quarter-Turn Operation |
90° rotation from fully open to fully closed enables fast response — ideal for emergency shut-off and automated systems. |
|
Easy Maintenance |
Flanged connections allow the valve to be removed from the line without cutting pipe or moving adjacent pipes — reduces downtime and maintenance costs. |
|
Bi-Directional Sealing |
Seals effectively against pressure from either direction, preventing installation errors. |
|
Actuator Ready |
Top flange conforms to ISO 5211 standards, allowing direct mounting of manual levers, gear operators, electric actuators, or pneumatic actuators. |
|
Large Diameter Capability |
Designed specifically for DN1200–DN2200 applications, with reinforced discs and heavy-duty stems to handle higher torque and pressure in large water mains. |
Flanged Butterfly Valve vs. Wafer Butterfly Valve – Quick Comparison
|
Parameter |
Flanged Butterfly Valve |
Wafer Butterfly Valve |
|
Connection Type |
Integral flanges (bolted to pipe flanges) |
Clamped between pipe flanges (no integral flanges) |
|
Removal from Pipeline |
Easy — unbolt valve, line remains intact |
More difficult — flange bolts pass through valve body, loosening affects adjacent pipes |
|
Rigidity & Strength |
Higher — ideal for large diameters and high pressure |
Moderate — suitable for standard pressure |
|
Typical Diameter Range |
DN50 – DN2200 |
DN50 – DN1200 |
|
Weight |
Heavier (due to integral flanges) |
Lighter |
|
Installation Time |
Moderate (align flanges, insert bolts) |
Faster (center between flanges, insert bolts) |
|
Cost |
Higher (more material, more machining) |
Lower |
|
Best For |
Large mains, high pressure, frequent maintenance, industrial systems |
General service, space-constrained, budget-sensitive projects |
Seat Material Selection Guide
|
Seat Material |
Temperature Range |
Best For |
|
EPDM |
-10°C to +120°C |
General water, cold/hot water, diluted acids, alkaline solutions — most common for water systems. |
|
NBR |
-10°C to +90°C |
Oily water, fuel, gasoline, mineral oils — suitable for industrial water with oil content. |
|
PTFE |
-20°C to +180°C |
Strong chemicals, acids, solvents, steam — excellent chemical resistance but higher torque. |
|
VITON (FKM) |
-15°C to +200°C |
High-temperature water, aggressive chemicals, fuels, mineral acids — premium chemical/thermal resistance |
