Incoloy 800H is a nickel-iron-chromium alloy optimized for high-temperature structural applications, offering superior creep and rupture strength above 1100°F (593°C).
This article details the primary types of Incoloy 800H flanges, highlighting their design, advantages, and applications.
Weld Neck Flanges
Weld neck flanges, also known as welding neck flanges, feature a long tapered hub that transitions smoothly to the pipe wall, providing reinforcement against high pressure and temperature fluctuations. In Incoloy 800H, these flanges are forged from bars or plates per ASTM B408 and B564, with the hub welded directly to the pipe end using techniques like TIG or MIG.
The advantage of Incoloy 800H weld neck flanges lies in their enhanced creep resistance. For instance, in ethylene cracking furnaces or hydrocarbon processing, these flanges prevent leaks and maintain system efficiency, reducing maintenance costs by up to 30% compared to standard alloys.
Our factory produces weld neck flanges in sizes from 1/2" to 60" NPS, with pressure ratings from Class 150 to 2500, adhering to ASME B16.5 dimensions. The raised face (RF) or ring-type joint (RTJ) sealing surfaces ensure gas-tight connections even in sulfur-containing atmospheres.
Slip-On Flanges
Slip-on flanges slide over the pipe end and are fillet-welded both inside and outside for a secure attachment. Manufactured from Incoloy 800H sheet or plate via cutting and machining per ASTM B409, these flanges offer a cost-effective alternative to weld necks while maintaining high-temperature strength.
Incoloy 800H enhances slip-on flanges with excellent resistance to oxidation and nitriding, making them suitable for moderate-pressure systems up to 1100°F (593°C).
Their lower hub profile reduces material usage, lowering costs without compromising the alloy's inherent corrosion resistance in environments like flue gas desulfurization or chemical processing. Advantages include easy alignment during installation and reduced welding time, which minimizes distortion in heat-sensitive applications.
Available in our lineup from NPS 1/2" to 24", with flat face (FF) or raised face options, these flanges meet DIN 17460 and EN 10095 standards. In power plant superheaters or industrial furnaces, Incoloy 800H slip-on flanges provide reliable service, extending equipment life and ensuring compliance with stringent safety regulations.
Socket Weld Flanges
Socket weld flanges incorporate a recessed socket where the pipe end is inserted and fillet-welded from the outside, creating a smooth bore for fluid flow. Forged from Incoloy 800H per ASTM B564, these flanges are ideal for small-diameter, high-pressure lines.
The alloy's high nickel (30–35%) and chromium (19–23%) content imparts outstanding resistance to stress corrosion cracking, a critical benefit in socket weld designs prone to vibration. At elevated temperatures, Incoloy 800H socket weld flanges exhibit minimal creep, ensuring joint stability in applications like nuclear steam generators or acetic acid production.
Our production includes sizes up to NPS 3", with Class 300 to 1500 ratings, featuring precise socket depths for optimal pipe insertion. In petrochemical manifolds or valve connections, these flanges reduce leak risks and enhance system integrity.
Their compact design and robust weld strength make Incoloy 800H socket weld flanges essential for space-constrained, high-reliability setups.
Threaded Flanges
Threaded flanges screw directly onto pipe threads, eliminating welding for quick assembly in low-pressure systems. Machined from Incoloy 800H bars under ASTM B408, they feature NPT or BSP threads for secure, leak-proof connections.
Incoloy 800H's thermal stability prevents thread galling or seizing at temperatures up to 1500°F, offering advantages over carbon steels in cyclic heating environments. This type excels in temporary installations or where welding is impractical, such as in hazardous chemical lines or instrumentation.
We offer threaded flanges in NPS 1/2" to 4", Class 150 to 900, with anti-corrosive coatings available. In heat exchangers or diphenol processing, they provide easy maintenance and corrosion resistance, reducing downtime. Incoloy 800H threaded flanges to achieve efficient, weld-free solutions that maintain performance in aggressive media.
Lap Joint Flanges
Lap joint flanges consist of a stub end and a loose backing flange, allowing rotation for bolt alignment. The flange ring is forged from Incoloy 800H per ASME SB564, while the stub end matches the pipe material.
This design leverages Incoloy 800H's carburization resistance, ideal for systems requiring frequent disassembly. Advantages include cost savings on exotic alloys for the ring only and reduced stress from misalignment. In vinyl chloride cracking or furnace fixtures, lap joint flanges facilitate inspections without compromising the alloy's high-temperature prowess.
Our range covers NPS 1/2" to 24", with RF or FF faces, compliant with ISO 9723. Their flexibility and durability make Incoloy 800H lap joint flanges a smart investment for modular piping in corrosive, hot settings.
Blind Flanges
Blind flanges seal pipe ends or vessel openings, providing a solid barrier without passages. Die-forged or machined from Incoloy 800H plates per ASTM B409, they withstand full system pressure.
Incoloy 800H blind flanges resist sulfidation and intergranular corrosion, crucial for blanking off lines in petrochemical plants or pressure testing. Their flat or raised faces ensure tight seals with gaskets, preventing leaks in high-heat scenarios.
Produced in sizes NPS 1/2" to 60" and Class 150 to 2500, our blind flanges meet VdTÜV 412 standards. In nuclear or acidic applications, they offer unmatched safety and longevity, making them indispensable for isolation tasks.
Long Weld Neck Flanges
Long weld neck flanges extend the hub for direct vessel attachment, acting as integral nozzles. Machined from Incoloy 800H forgings per ASTM B564, they eliminate additional welds.
Incoloy 800H's oxidation resistance at 1800°F (982°C) suits them for high-stress boiler components or reactors. Advantages include reduced leak paths and enhanced fatigue life in cyclic services.
Our offerings span NPS 1/2" to 12" and custom lengths, meeting ASME Section VIII. In thermal processing or nuclear applications, long weld-neck flanges ensure structural integrity, proving their worth in critical infrastructure.
Conclusion
Regardless of the flange type selected-whether it is the robust Weld Neck for your high-pressure steam lines or the economical Lap Joint for your low-pressure vents-ensure your manufacturer provides a Mill Test Certificate (MTC) verifying both chemistry and grain size.
At JN, we do not just sell flanges; we sell the assurance that your high-temperature system will hold its integrity when the heat is on.
