Double-Flanged Triple-Offset Butterfly Valve

The Double-Flanged Triple-Offset Butterfly Valve delivers bi-directional, bubble-tight shutoff across critical thermal and high-pressure fluid systems. Utilizing non-rubbing triple-eccentric geometry alongside integrated rigid flange connections, this valve provides quarter-turn mechanical isolation for steam, hydrocarbon, chemical, and offshore piping installations.

Triple-Eccentric Geometry: Eliminates seat friction during rotational travel, extending seal longevity and reducing operating torque.

Metal-to-Metal Bubble-Tight Sealing: Achieves zero-leakage performance under thermal extremes ranging from cryogenic conditions to elevated process temperatures.

Double-Flanged Body Architecture: Provides independent upstream and downstream bolting, enabling safe line maintenance and dead-end isolation.

Anti-Blowout Shaft Retention: Internal shoulder design secures the stem to prevent shaft ejection under sudden pressure surges.

Laminated Metal-Graphite Seal Ring: Adjusts dynamically to body seat contours under continuous thermal cycling.

Triple Offset Geometry:
• Offset 1: Shaft axis positioned behind the plane of the sealing seat.
• Offset 2: Shaft axis displaced laterally from the pipe centerline.
• Offset 3: Inclined cone profile of the seat axis eliminates friction throughout the full 90-degree stroke.

Integral Flanged Body: Cast solid flanges comply with ASME B16.5 and ASME B16.47 dimensional standards.

Blowout-Proof Shaft: Heavy-duty stem retaining mechanism compliant with API 609 requirements.

Field-Replaceable Seal: Disc-mounted laminated stainless steel and flexible graphite element allows direct inline replacement.

Operation relies on a camming action derived from the angled elliptical cone profile. Upon rotation, the disc seal instantly disengages from the body seat without rubbing or scraping. At closure, mechanical torque forces the flexible metallic laminate against the Stellite-faced solid body seat, creating a continuous, uniform line-of-contact seal.

Dimensional Configurations: Available in standard double-flange face-to-face dimensions including ISO 5752 Series 14 (long pattern) and Series 13 (short pattern).

Flange Finishing: Serrated spiral or smooth machine finish options compliant with ASME B16.5 requirements.

Pipeline Anchoring: Rigid double-flange connection securely isolates piping stresses and permits downstream line dismantling while under pressure.

Manual Drive: Heavy-duty enclosed worm gear operators featuring adjustable travel stops and visual position indication.

Pneumatic Control: Double-acting or spring-return rack-and-pinion actuators fitted with limit switch boxes, electro-pneumatic positioners, and air filter regulators.

Electric Drive: Smart quarter-turn actuators providing modulating control (4-20mA signal input/output) and fieldbus connectivity.

Hydraulic Systems: High-torque hydraulic actuators engineered for rapid emergency shutdown (ESD) routines.

Hydrocarbon Refining: High-temperature fluid handling, catalytic cracking processes, and flare system isolation.

LNG Pipelines: Cryogenic fluid transfer, regasification plant lines, and boil-off gas containment.

Power Plants: Main steam isolation lines, boiler feed circuits, and high-pressure steam extraction.

Offshore Production: FPSO process piping, seawater injection, fire mains, and ballast control systems.

Chemical Plants: Corrosive chemical handling, thermal fluid circulation, and solvent recovery loops.

For accurate sizing and structural selection, submit the following engineering parameters:

Process Medium: Fluid physical state, chemical composition, viscosity, and solid particulate presence.

Pressure Conditions: Maximum continuous working pressure and differential shutoff pressure (ΔP).

Temperature Requirements: Minimum and maximum continuous process temperature.

Flow Parameters: Calculated flow coefficient (Cv), velocity, and allowable pressure drop.

Flange Specifications: Pipe flange pressure rating, facing type, and schedule wall thickness.

Actuator Requirements: Control mode, signal interface, instrument air supply pressure, and fail-safe action mode.

Factory quality verification includes mandatory procedures prior to shipment:

Hydrostatic Shell Testing: Conducted at 1.5 times nominal cold working pressure per API 598.

High-Pressure Seat Testing: Hydrostatic seal evaluation at 1.1 times nominal pressure verifying zero-leakage shutoff.

Low-Pressure Air Testing: Pneumatic seat testing at 80 PSI (5.5 bar) for low-pressure bubble tightness verification.

Fugitive Emissions Testing: Helium leak testing conducted under ISO 15848-1 protocols.

Non-Destructive Testing (NDT): Radiographic (RT), Liquid Penetrant (PT), Magnetic Particle (MT), and Ultrasonic (UT) casting examinations as specified by project requirements.

Material Documentation: Fully traceable EN 10204 3.1 material test certificates provided for all pressure-containing components.

Corrosion-Resistant Alloys: Special casting and forging options in Monel, Titanium, Hastelloy, and Alloy 20.

Extended Stem Extensions: Custom extended bonnets tailored for cryogenic temperatures (-196°C) or thick pipe insulation systems.

Steam Heating Jackets: Fully jacketed valve bodies preventing fluid solidification in asphalt and sulfur services.

Protective Coatings: Multi-layer epoxy paint systems, fluoropolymer coatings, and specialized marine corrosion protection.

Engineering Drawings: Dimensional line drawings, 2D CAD files (DWG/DXF), and 3D STEP models for piping modeling.

Data Sheets & Catalogs: Technical specifications, pressure-temperature rating curves, and Cv flow capacity charts.

Installation & Maintenance Manuals: Detailed instructions for flange bolt torque patterns, gland packing adjustment, and seat replacement procedures.

Quality Certification Samples: Representative EN 10204 3.1 chemical analysis and mechanical testing records.