Concentric butterfly valve derives its name from its structural characteristic: the centerline of the disc and seat coincides along the same axis. Its working principle involves rotating the disc mounted on the valve stem to adjust the flow passage area through the valve body, thereby achieving flow regulation or fluid shut-off. Concentric butterfly valves are commonly used in applications demanding high sealing integrity and precise medium flow control.
Working principle
The essence of the concentric butterfly valve lies in its ingenious utilization of fluid pressure to achieve bidirectional zero-leakage sealing, with an exceptionally clear and efficient operating sequence:
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Open State: The actuating mechanism (handwheel, gearbox, or actuator) rotates the valve stem by 90°(typically clockwise to close, counterclockwise to open). The stem drives the vertically mounted disc to rotate from a position perpendicular to the flow path to a position parallel with the flow path. In this state, only the disc thickness presents minimal flow resistance, allowing near-unimpeded medium passage.
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Closing Process: The actuating mechanism reverses the stem rotation by 90°. The disc rotates back from parallel to perpendicular alignment relative to the flow path.
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Sealing Formation (Critical Phase): As the disc approaches or reaches the closed position:
The elastomeric seat (rubber or PTFE sealing ring) embedded along the disc’s circumferential edge contacts the sealing surface on the valve body interior.
Types of double offset butterfly valves
In terms of end connection
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Flanged Connection: The most common method, suitable for applications requiring high sealing integrity and large pipe diameters. It features flanges at both ends, bolted to pipeline flanges.
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Wafer Connection: Lacks end flanges. It utilizes a clamped structure secured between pipeline flanges via bolts, ideal for small-to-medium bore pipelines.
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Lug Connection: Integral lugs on the valve body allow direct bolting to pipeline flanges or fittings. It can be applied in industries demanding high-strength joints and reliable sealing.
In terms of driving mode
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Hand Lever Operation: Manual control for small-bore valves (≤DN200). Lightweight operation with intuitive handling
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Worm Gear Operator: Torque amplification for large-bore valves (≥DN200). Reduced operating effort with optional position indicator
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Electric Actuator: Automated control for remote/programmable switching & flow regulation. Integrated smart control systems.
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Pneumatic Actuator: Rapid response. Designed for explosion-proof or fast-cycling applications (e.g., chemical safety systems)
Butterfly valves often experience issues during prolonged operation, such as seizure during actuation, lubricant leakage, and corrosion. Selecting high-quality worm gear operators is critical for minimizing long-term operation and maintenance costs. Taloar worm gear operators achieve IP67 sealing protection, while all butterfly valve bolts, nuts, and fasteners utilize stainless steel material. This design prevents corrosion caused by rainwater exposure and condensation during operation, ensuring extended service life.
Taloar butterfly valve worm gear operators utilize high-temperature lithium complex grease formulated with industrial-grade compounds. This prevents grease liquefaction in high-temperature environments, ensuring reliable performance and extended service life.
The worm gear operator’s mechanical construction combined with premium EPDM sealing materials ensures zero water ingress during rain exposure or condensation formation, achieving IP67 protection class to prevent corrosion.
The use of high-strength ASTM-compliant stainless steel bolts, nuts, and fasteners prevents rust formation caused by rainwater exposure and condensation buildup.
Application:
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Critical Infrastructure Applications:
Municipal Water Systems: Raw/treated water pipelines in purification plants, municipal supply/firefighting networks & booster pump stations, secondary water supply systems and wastewater treatment processes (equalization basins, clarifiers, aeration tanks, effluent discharge)
Building Services: Cold/hot water systems in high-rise buildings, fire sprinkler/hydrant systems, pump room inlet/outlet pipelines and roof tank inflow/outflow control
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Environmental Temperature Regulation:
HVAC Systems: Main and branch pipelines of central air conditioning chilled/cooling water circulation systems, inlet/outlet connections of heat exchangers, district heating/cooling pipe networks, water circuit control for fresh air handling units and fan coil units.
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Industrial Lifelines:
General Industry: Main & branch pipelines for factory compressed air systems, recirculating cooling water systems, low-pressure process water lines (cooling, cleaning, conveyance) and inlet/outlet connections for general liquid/gas storage tanks
Chemical & Pharmaceutical: Low-pressure corrosive media pipelines (fluoropolymer-lined sealing required), purified water/WFI (Water for Injection) systems (stainless steel + sanitary-grade sealing) and process distribution lines (material compatibility-specific)
Power & Energy: Power plant circulating water systems, auxiliary cooling water systems and demineralized water systems
Food & Beverage: Process water lines, CIP (Clean-in-Place) pipelines, product transfer lines (*316L stainless steel + food-grade EPDM/FKM seals meeting FDA/3A certifications*)
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Special Application Fields:
Marine Shipping: Ballast water systems, bilge drainage systems, seawater cooling systems and potable water systems
Irrigation Agriculture: Main pipelines for large-scale farmland irrigation and pump station valve control
Pool Water Treatment: Recirculation filtering system pipelines
As essential shut-off devices, zero leakage is a fundamental requirement for butterfly valves. The valve seat—the core sealing component—directly determines service life. Taloar utilizes imported premium rubber compounds and implements rigorous quality control standards for: hardness, weather resistance, chemical corrosion resistance, elastic recovery and abrasion resistance.
Vulcanized EPDM rubber thermally bonded to the valve body, forms a seamless integration. It features a wide sealing edge with integrated sealing rib, designed as a non-replaceable valve seat.
Groove-embedded EPDM construction achieves full surface contact with the valve body. It features a wide sealing edge with integrated sealing rib, designed as a replaceable valve seat.
It is not recommended to use EPDM rigid valve seat due to: High operating torque requirements, excessive clearance gaps, narrow rubber sealing profile and lack of integrated sealing rib.
The valve body is available in double flanged, lug, or wafer connection styles (with double flanged and lug types suitable for end-of-line applications). The seat utilizes imported EPDM or NBR rubber compounds, offering customers the choice between groove-embedded seat design or direct vulcanization onto the valve body (typically applied to flanged bodies, ensuring gapless integration between seat and body for secure installation with minimal deformation risk).
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The valve seat features an integrated sealing rib, eliminating the need for additional flange gaskets and requiring lower operating torque;
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The disc employs a solid-shaft or pinless split-shaft design, with an enlarged stem collar maximizing seat contact area to ensure zero leakage;
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Disc materials include 304/316 stainless steel, nylon-coated ductile iron, or epoxy-coated ductile iron;
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The top flange complies with ISO 5211 standards for direct mounting of electric/pneumatic actuators;
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Valve size≤6" allow handwheel or gear operation; those ≥8" require gear operation due to excessive torque;
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5-year quality guarantee.
As a professional valve manufacturer, Taloar is dedicated to offering its customers the highest quality concentric butterfly valve products on the market. Should you have any special customized products, please contact us.
If you need to keep up with innovations and technological advancements in concentric butterfly valve, Taloar will support you! For more details, please contact sales@taloar.com or WhatsApp 008618112507128.
