Butterfly Valves

LPB12 Triple Eccentric Metal Sealing Butterfly Valve

Triple eccentric metal sealing butterfly valve that replaces the elastomer seat with a precision-engineered metal-to-metal sealing system—delivering zero-leakage shutoff at extreme temperatures, high pressures, and in the most aggressive process media where resilient-seated valves simply cannot survive.

Product Description

Built on a triple-eccentric geometry—combining a shaft offset from the disc centerline, a shaft offset from the pipe centerline, and a conical seat angle machined into the sealing surface—this valve achieves a true cam-action opening and closing motion. The disc lifts completely clear of the seat within the first few degrees of rotation, eliminating all sliding friction and seat wear throughout the operating cycle. Sealing is accomplished not by elastomer compression but by a mechanical interference fit between a laminated stainless steel / graphite seat ring and a hard-faced (Stellite, tungsten carbide, or chrome-plated) disc edge, producing a metal-to-metal, bubble-tight closure that is inherently fire-safe and unaffected by thermal cycling. The result is a valve that maintains API 609 Category B / API 6D zero-leakage performance from cryogenic LNG service at −196 °C to superheated steam at 550 °C and beyond, at pressures up to Class 2500 (PN 420). With no soft seat to degrade, swell, or burn, the triple eccentric metal-sealed butterfly valve is the definitive isolation and throttling solution for oil & gas, petrochemical, power generation, and heavy industrial applications where uptime, safety, and lifecycle cost are paramount.

Key Features

Triple-offset geometry – Shaft-to-disc offset, shaft-to-pipe offset, and conical seat angle combine to produce a friction-free cam action; the disc clears the seat instantly upon opening, eliminating wear and extending service life by 3–5× over double-offset designs.
Metal-to-metal, zero-leakage seal – Laminated SS 316 / flexible graphite seat ring mates with a hard-faced disc edge (Stellite 6, WC-Co, or hard chrome), achieving API 609 Cat. B / API 6D / EN 12266-1 Rate A tightness with no elastomer dependency.
Inherently fire-safe – No soft seat to combust; the all-metal sealing system maintains shutoff integrity during and after a fire event, compliant with API 607 / ISO 10497 without secondary devices.
Extreme temperature envelope – Standard range −196 °C to +550 °C (−320 °F to +1022 °F); extended designs available to +815 °C for flue-gas and turbine bypass duty.
High-pressure capability – Rated from Class 150 through Class 2500 (PN 16 – PN 420), suitable for mainline isolation and letdown service.
Bi-directional shutoff – Symmetrical seat geometry provides equal sealing performance in both flow directions, simplifying piping layout and inventory.
Low torque, high Cv – The conical seat and offset pivot minimize operating torque while the full-bore disc profile maximizes flow coefficient, reducing actuator size and energy consumption.
Anti-galling & anti-seize design – Precision-ground seat surfaces with controlled surface finish and optional anti-seize coatings prevent cold-welding in high-temperature or cryogenic cycling.
Robust body & disc materials – WCB / LCB / WC6 / WC9 / CF8M / CF3M / duplex / super-duplex / Inconel / Monel / titanium bodies and discs to match any process fluid.
Fugitive-emission compliant – Live-loaded graphite or PTFE stem packing meets ISO 15848-1 / API 622 / TA-Luft for VOC-sensitive installations.
ISO 5211 actuator-ready – Standardized top flange accepts manual gear operators, pneumatic, hydraulic, and electric actuators; SIL-rated ESD packages available.
Wide size range – 2″ (DN 50) through 120″ (DN 3000) in wafer, lug, and butt-weld end connections per ASME B16.5 / B16.47 / EN 1092-1.

Typical Applications

Oil & gas upstream / midstream – Wellhead isolation, pipeline block valves, pig-launcher manifolds, and compressor-station bypass where Class 900–2500 metal-seated shutoff is mandatory.
Refining & petrochemical – FCCU, hydrocracker, and coker unit isolation; high-temperature hydrogen and sour-gas (H₂S) service requiring NACE MR0175 / ISO 15156 compliance.
Power generation – Main steam isolation, turbine bypass, feedwater, and flue-gas desulfurization (FGD) systems operating at 500 °C+ and cyclic thermal shock.
LNG & cryogenic processing – LNG transfer lines, boil-off gas headers, and cod-box isolation at −196 °C with extended-stem, low-temperature-rated trim.
Chemical & pharmaceutical – Aggressive acid, caustic, and solvent services where elastomer seats would swell or dissolve; duplex / Hastelloy / titanium construction available.
Mining & slurry – High-pressure tailings, thickener underflow, and abrasive slurry pipelines benefiting from the wear-resistant hard-faced disc and friction-free seat engagement.
Marine & offshore – Seawater cooling, ballast, and fire-water systems requiring compact, lightweight, corrosion-resistant isolation

Specifications

Valve Size:
NPS2 - NPS120;
DN50 - DN3000
Pressure Class:
ASME Class 150, Class 300, Class 600, Class 900, Class 1500, Class 2500;
DIN PN10, PN16, PN25, PN40, PN63, PN100, PN160, PN260
Operating Temperature:
-196 to +816 °C / -320 to +1500 °F
Process Connection Type:
Flanged, Wafer, Lugged, Butt Welded
Valve Bonnet:
Standard, Heating Extension, Cooling Extension
Stem Seal:
Adjustable Packing
Seat Leakage:
Class V, VI (FCI-70.2) Standard Leakage Rates
Flow Characteristics:
Linear
Critical Service:
General Service, Low Temperature, Dirty Service, Steam Condition, Erosive, Corrosive, Outgassing
Valve Actuator:
Electric, Hydraulic, Pneumatic, Lever, Gear, Electro-Hydraulic
Valve Accessories:
Pneumatic Positioner, Electro Pneumatic Positioner, Limit Switch, SOV, Air lock relay, Volume Booster, AFR, Position Transmitter
Certifications:
PED, NACE, ATEX, Fire Safe, SIL capable, Fugitive Emission
Media:
Specialty Gases, Steam, Liquids, Air, Inert Gas, Water, Air
Other Configurations:
Contact your local Lapar business partner or sales office to learn about additional specifications or options for this product.