Precision Forged Flanges & Fittings - Built for Global Markets

ASME B16.5 Weld Neck Flange (WN)

American standard weld neck flange with tapered hub. ASME B16.5 (up to NPS 24) & ASME B16.47 Series A/B (NPS 26-60). 1/2"-60", 150-2500LB.

Weld Neck Flange (WN)

The ASME B16.5 Weld Neck Flange (WN) features a long tapered hub that transitions smoothly into the pipe bore, providing the highest mechanical strength and fatigue resistance among all flange types. The hub is butt-welded to the pipe, making it the preferred choice for critical service applications involving high pressure, high temperature, or cyclic loading conditions.

JIAJI FORGING manufactures Weld Neck flanges in austenitic stainless steel, duplex & super duplex stainless steel (UNS S32205, S32750), and nickel alloys (Inconel, Hastelloy, Monel) for the global market.

Applications

  • Oil & gas pipelines (onshore & offshore)
  • High-pressure steam systems
  • Petrochemical & refinery
  • Power generation plants
  • Subsea umbilicals & manifold
  • Cryogenic LNG applications
  • Chemical processing plants
  • Marine & shipbuilding

Pressure Ratings Available

  • Class 150 (PN20) / Class 300 (PN50)
  • Class 400 / Class 600 / Class 900
  • Class 1500 / Class 2500

Facing Types (ASME B16.5)

RF
Raised Face

FF
Flat Face

RTJ
Ring Joint

ASME B16.5 Weld Neck Flange (WN)

Specifications

ParameterSpecification
StandardASME B16.5 (NPS 1/2"-24")
ASME B16.47 Series A (NPS 26-60)
Size RangeNPS 1/2" - NPS 60" (DN15 - DN1500)
Pressure RatingClass 150 / 300 / 400 / 600 / 900 / 1500 / 2500
Face FinishRaised Face (RF), Flat Face (FF), Ring Type Joint (RTJ)
Materials304/304L (F8), 316/316L (F8A), 321 (F8C), 347 (F8D), 310S, 904L, 2205 (F51), 2507 (F53), Inconel 625, Inconel 825, Hastelloy C276, Monel 400
SurfaceAnti-rust oil, black, galvanized, painted

Available Materials

Austenitic Stainless Steel

UNS / AISIASTM
304 / 304LA182 F8 / F8A
316 / 316LA182 F8 / F8A
321A182 F8C
347A182 F8D
310SA182 F310
904LA182 F904L

Duplex & Super Duplex

UNSASTM
S31803 (2205)A182 F51
S32205 (2205)A182 F51
S32750 (2507)A182 F53
S32760A182 F55

Nickel Alloys

UNS / AlloyASTM
N06625 (Inconel 625)A182 F65
N08825 (Incoloy 825)-
N10276 (Hastelloy C276)-
N04400 (Monel 400)-

Marking & Quality

Per ASME B16.5, each flange is permanently marked with: Manufacturer / Material / Pressure Class / Size / Face Type / Heat No.

Example: JIAJI · F316 · WN · 4" · CL150 · RF · BATCH-2024

Optional: NACE MR0175 / ISO 15156, 3.1 / 3.2 inspection certificates (EN 10204), API 6A, CE marking (PED 2014/68/EU) available upon request.

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ASME B16.5 Blind Flange. Full bore closure. NPS 1/2"-24". Class 150-2500.

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ASME B16.5 Slip On Flange. Cost-effective. NPS 1/2"-24". Class 150-300.

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Socket Weld Flange (SW)

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