The large bore water supply double eccentric double flange butterfly valve is engineered for bulk water transmission, municipal distribution networks, irrigation mains, hydropower intake lines and industrial raw-water circuits. Built by Trekre Valve, a professional China valve manufacturer, this double flange butterfly valve combines compact face-to-face dimensions with reliable metal-to-metal sealing performance across large nominal diameters where gate valves would be heavy, slow and costly to maintain.
Double eccentric geometry moves the stem axis behind the disc centre and offsets the disc sealing track from the body seat centreline. During the first degrees of opening, the disc lifts away from the seat instead of scraping across it. That reduces operating torque, extends seat service life and makes the valve suitable for frequent throttling or emergency isolation in water supply plants, booster pump stations and district metering zones.
Large bore double flange butterfly valve for water supply
Connection type: double flanged ends for direct bolting between pipeline flanges
Structure: double eccentric (high performance) disc and body design
Size range: 1 1/2″ to 80″ (DN40 to DN2000)
Pressure rating: PN10, PN16, PN25, Class 150 and Class 300 (project specific)
Body material: WCB carbon steel, CF8/CF8M stainless steel, duplex 2205/2507
Disc and seat: stainless steel or hard alloy overlay for metal hard seal
Operation: worm gear handwheel, electric actuator or pneumatic actuator
Double eccentric double flange butterfly valve specifications
Trekre manufactures this large bore butterfly valve series for clean water, raw water, seawater desalination brine and neutral industrial fluids within the pressure-temperature limits confirmed for the selected body, seat, stem sealing, bearings and complete valve assembly. The double flange body allows stable alignment on large-diameter pipework and supports removal of one flange joint for inline maintenance without disturbing the entire spool.
Design and testing can follow GB/T 12238, API 609, EN 593, MSS SP-67 and project-specific water-works specifications. Each valve is hydrostatically tested for shell and seat integrity before dispatch from our Wuxi factory. Flange drilling is available to ANSI B16.5, EN 1092-1, DIN PN formats and JIS B2220 upon request.
Structural composition and sealing principle
Main components include the double flanged valve body, double eccentric disc, multi-layer metal seat ring, stem with anti-blowout retention, secondary stem seals, bearing bushes and the selected drive device. The disc rotates approximately 90° between fully open and fully closed positions. Because the sealing surfaces engage only in the final closing segment, wear on the metal seat is minimized compared with concentric soft-seated designs used at smaller sizes.
The metal hard seal configuration targets applications where elastomer seats would degrade under higher temperature, abrasive silt load or prolonged UV exposure in outdoor water galleries. Optional stainless steel or hard-facing overlays on the disc edge and body seat improve resistance to cavitation damage at pump discharge points and to fine sand particles in river intake systems.
Material options for water supply duty
Valve body: WCB cast carbon steel for standard municipal water; CF8 (304) or CF8M (316) stainless steel for coastal, desalination or mildly corrosive sources; duplex steel for higher chloride content.
Disc: matching body material or stainless steel with surface treatment; hard alloy seat overlay available for abrasive media.
Stem: stainless steel 410, 304 or 316 with ground surface and low-friction packing set.
Fasteners and hardware: stainless steel grade selected to match pipeline and environmental conditions.
Coating: fusion-bonded epoxy or polyurethane internal and external coating per AWWA C550 or project paint specification for buried or submerged service.
Drive methods and control integration
Worm gear operation is the most common choice for large bore manual isolation valves above DN300. The gear unit provides self-locking hold in any intermediate position and reduces handwheel rim force to practical levels for field operators. Gearboxes can include mechanical position indicators, limit stops and padlock provisions for line security.
Electric actuation suits remote SCADA-controlled pump stations, reservoir inlet works and automated network flushing sequences. Actuator sizing considers differential pressure across the disc, required fail-safe action (open or close on power loss) and control signal type (on-off contact or 4–20 mA modulating). Pneumatic actuators deliver fast stroke times for emergency shutdown on high-capacity transmission lines where compressed air infrastructure is already present.
Confirm the selected valve’s mounting interface, shaft coupling, required torque and travel, and any bracket or adapter before approving an actuator replacement; an ISO 5211 reference alone does not establish direct interchangeability.
Typical water supply and industrial applications
Municipal water treatment plant inlet, outlet and filter backwash isolation
Raw water and finished water transmission mains above DN600
Irrigation district headworks, canal regulation and pump manifold control
Fire water ring mains and large building HVAC chilled-water headers
Power plant cooling water, steel mill process water and mining dewatering lines
Metallurgy, petrochemical utility water and general HVAC balancing duty within rated temperature limits
Performance advantages of double eccentric design
Opening torque remains low even at large bore sizes, reducing gearbox size and actuator cost.
Three-dimensional disc path achieves tight metal sealing with minimal wedging force, supporting bi-directional shut-off in many configurations.
Streamlined disc profile produces lower head loss than gate valves of equivalent size, saving pumping energy on long transmission routes.
Short face-to-face length simplifies installation in existing valve chambers originally sized for butterfly rather than gate valves.
Proven service record in water, gas and air pipelines extends the product platform from municipal networks into adjacent industrial sectors without design change.
Selection and ordering information
When requesting a quotation from Trekre Valve, please confirm nominal diameter, pressure class, flange standard and drilling table, body and trim material, media composition and temperature, flow direction if uni-directional seat is required, operation type (manual gear, electric or pneumatic), coating specification and any actuator control or feedback accessories. Our engineering team can recommend the optimal double eccentric double flange butterfly valve configuration for new pipeline construction or like-for-like replacement in aging water infrastructure.
As a dedicated China valve manufacturer, Trekre maintains production, inspection and spare-part support for large bore butterfly valves from stock components through fully custom builds. Contact us for dimensional drawings, torque data and delivery schedules tailored to your water supply project timeline.
Installation, maintenance and service life
Install the double flange butterfly valve with the disc in the slightly open position to prevent seat damage during bolt tightening. Align flanges carefully on large bore lines to avoid body stress. Allow sufficient clearance above the valve for actuator removal and stem packing adjustment. In buried water mains, specify extension stem and floor stand configurations when the handwheel must reach ground level.
Routine maintenance includes packing gland inspection, gear lubrication and periodic exercise of the valve through a full stroke to dislodge sediment that may accumulate on the seat in raw water service. Metal hard seal pairs can be refurbished by machining or overlay welding when wear is localized, extending total valve life beyond elastomer-seated alternatives in demanding bulk water applications.
Quality control from China valve factory
Every large bore water supply butterfly valve from Trekre Valve passes material traceability review, dimensional inspection against approved drawings, non-destructive testing on critical welds where applicable and pressure testing before release. Factory test reports, material certificates and installation manuals are supplied with each order to support water authority approval processes and third-party inspection witness requirements.
Our Wuxi production centre integrates CNC machining, assembly benches for actuator pairing and final packaging for domestic and export shipment. Lead times for common carbon steel sizes are competitive, while special materials and oversized diameters are scheduled with transparent milestone updates for EPC contractors managing critical path pipeline commissioning.
This large-bore butterfly-valve page covers a double-eccentric, double-flanged configuration. If hard seating is specified, the complete assembly still needs an approved pressure-temperature envelope. A hard seat alone does not establish a numerical high-temperature capability.
Product Overview
The disc turns within the selected double-eccentric arrangement, and the flanged body must be matched to the mating pipeline. Seat, stem sealing, bearings, body and drive can impose different service constraints. Evaluate the complete construction and project duty rather than applying an unsupported series-wide temperature range.
Selection and Ordering Notes
- Provide actual design and operating pressure and temperature, medium and required shutoff duty.
- Confirm the selected hard-seat or other sealing arrangement and complete assembly rating.
- Identify flange drilling, size, face-to-face dimensions and installation-space requirements.
- Request the actual actuator or gearbox sizing and model-specific installation and maintenance documents.
Related information: Review butterfly-valve configurations | Valve technical guidance | About Trekre.
Frequently Asked Questions
Does choosing a hard seat mean this valve is automatically suitable for my high temperature?
No. Hard seating may be considered as part of a high-temperature design, but suitability must be confirmed for the complete valve, including body, stem sealing, bearings and drive arrangement.
What temperature limit should I use for this valve?
Use the limit approved for the exact quoted configuration. The previous numerical temperature range did not have supporting product evidence and is not a verified rating for selection.
What should I send when replacing an existing large double-flanged butterfly valve?
Provide size, flange standard and drilling, face-to-face dimension, operating conditions and available drive and maintenance space. Request the selected assembly drawing and confirmed rating before approving fit.