OEM manufacturer ASME B16.5 (flange end) · Manufacturer standard / client drawing (barrel)
Long Weld Neck (LWN) Flanges
A long weld neck flange is a weld neck flange with an extended straight barrel instead of a short tapered hub, used mainly as a vessel or column nozzle. Teshi Group manufactures LWN flanges with flange ends to ASME B16.5 and barrels to manufacturer standard or client drawing.
Also called: LWN flange, long welding neck flange, nozzle flange, heavy barrel flange, equal barrel flange
What is a Long Weld Neck Flange?
A long weld neck (LWN) flange combines a flange and a thick-walled nozzle in one forging. The barrel, commonly 9″ or 12″ long or as specified, is welded into the shell of a vessel, column or header, and the pipe connects to the flange. ASME B16.5 fixes the flange ring dimensions but not the barrel, so barrel length and bore are set by the purchaser or manufacturer standard. Standard, heavy barrel (HB) and equal barrel (E) designs give different barrel profiles and wall thicknesses for nozzle reinforcement.
Key features
- One-piece forged flange and nozzle; no weld between them
- Flange end drilled and faced to ASME B16.5
- Standard, heavy barrel (HB) and equal barrel (E) designs
- Barrel length and bore to drawing
- RF, FF or RTJ facing
Specification
| Supply | OEM manufacturer — Teshi Group, India |
|---|---|
| Standard | Flange end to ASME B16.5; barrel to manufacturer standard / client drawing (not dimensioned in B16.5) |
| Size range | NPS ½″–24″ (flange end) |
| Pressure class | Class 150, 300, 600, 900, 1500, 2500 |
| Barrel length | Typically 9″ or 12″; other lengths to order |
| Facing | RF, FF, RTJ |
| Materials — carbon steel | ASTM A105 / A105N; ASTM A181 Cl 60, Cl 70; ASTM A266 Gr 2, Gr 4 (large forgings) |
| Materials — high-yield carbon steel | ASTM A694 F42, F46, F48, F50, F52, F56, F60, F65, F70 (MSS SP-44 grades F52–F70) |
| Materials — low-temperature carbon steel | ASTM A350 LF1, LF2 Cl 1, LF2 Cl 2, LF3, LF6, LF9 |
| Materials — alloy steel (Cr-Mo) | ASTM A182 F1, F2, F5, F5a, F9, F11 Cl 1 / 2 / 3, F12 Cl 1 / 2, F21, F22 Cl 1 / 3, F22V, F91, F92, F911; ASTM A336 F11, F22 (large forgings) |
| Materials — stainless steel | ASTM A182 F304, F304L, F304H, F304LN, F309H, F310, F316, F316L, F316H, F316LN, F316Ti, F317, F317L, F321, F321H, F347, F347H, F348 |
| Materials — 904L and 6Mo | 904L (ASTM A182 F904L, UNS N08904); 254 SMO / 6Mo (ASTM A182 F44, UNS S31254); AL-6XN (ASTM A182 F62, UNS N08367) |
| Materials — duplex stainless steel | ASTM A182 F51 (UNS S31803), F60 (UNS S32205, 2205) |
| Materials — super duplex stainless steel | ASTM A182 F53 (UNS S32750, 2507), F55 (UNS S32760), F61 (UNS S32550) |
| Materials — nickel alloys | ASTM B564 / B160 / B462: Nickel 200 / 201 (N02200 / N02201), Monel 400 (N04400), Monel K-500 (N05500), Inconel 600 (N06600), Inconel 625 (N06625), Inconel 718 (N07718), Incoloy 800 / 800H / 800HT (N08800 / N08810 / N08811), Incoloy 825 (N08825), Hastelloy C276 (N10276), Hastelloy C22 (N06022), Hastelloy B2 / B3 (N10665 / N10675), Alloy 20 (N08020) |
| Materials — titanium | ASTM B381 Grade F1, F2, F5 (Ti-6Al-4V), F7, F12 |
| Materials — copper-nickel | Cu-Ni 90/10 (UNS C70600) and 70/30 (UNS C71500), ASTM B151 bar; flanges to ASME B16.5 or EEMUA 145 |
| Grade availability | Every grade listed is made or supplied against order, with EN 10204 3.1 certificates (3.2 / third-party inspection when specified) and PMI on alloy, stainless, duplex and nickel grades. |
| Testing | Visual and dimensional inspection, PMI on alloy and stainless grades, hardness; UT, MPI/DPI as specified; UT of barrel when specified |
| Documents | EN 10204 3.1 mill test certificate; 3.2 / third-party inspection when the order specifies; dimensional inspection report; IBR certification when specified |
Applications
- Pressure vessel and column nozzles
- Heat exchanger shell nozzles
- Header and manifold branch connections
- Thermowell and instrument nozzles
- Reactor and drum outlets
Technical data sheets
Dimensions & weights
FAQ
Long Weld Neck Flange: common questions
Is a long weld neck flange covered by ASME B16.5?
Only the flange end. ASME B16.5 gives the flange OD, thickness, drilling and facing, but not the barrel length or bore. These are taken from the vessel drawing or a manufacturer standard.
What are heavy barrel and equal barrel LWN flanges?
A heavy barrel (HB) LWN has a thicker barrel wall for nozzle reinforcement. An equal barrel (E) LWN has the same OD along its full length. State the type, bore and barrel length on the order.
What information do you need to quote an LWN flange?
Give the NPS, class, facing, barrel type, barrel length, bore or wall thickness, material grade and quantity. A sketch of the nozzle helps. Teshi Group quotes in 24–48 hours.
Why use an LWN instead of a weld neck plus pipe?
The one-piece forging removes the circumferential weld between flange and nozzle pipe, gives a thicker nozzle wall for reinforcement, and simplifies fabrication and inspection of vessel and column nozzles.
Need a size or grade not listed here?
Our engineering team manufactures against your drawing or datasheet, with dimensional sign-off before dispatch.
Send us your specificationTraceability
From mill heat to your site
- 01
Approved mill material
Received against the mill certificate; heat number registered.
- 02
Forging & machining
Heat number carried through every stage in our Indian works.
- 03
PMI, dimensional & NDT
Every lot inspected to the governing standard; TPI witness on request.
- 04
Stamped & certified dispatch
Hard-stamped pieces with EN 10204 3.1 / 3.2 certificates.
Quick RFQ
Quote for Long Weld Neck Flange in 24–48 hours
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