FLANGE STANDARD LIBRARYAX FORGE · SPEC SHEET
SPEC SHEETNo. 289
ASME B16.47 Series B · ASME B16.47-2025

B16.47 B Class 400 26″ Weld Neck

DN650Weld NeckDimensions mmWeight kg
ASME B16.47 Series B · 26″ (DN650) · Class 400 · Weld Neck FlangeASME B16.47 Series B · 26″ (DN650) · Class 400 · Weld Neck Flange O.D. D 851.0 Bolt circle K 781.0 28ר38.1 Raised face Ø 711.0 Thickness C 88.9 RF height f 6.4 Length H 149.0 Hub Ø A 689.0 Weld end Ø 660.4 Both views share one scale (1:13); schematic only Unit: mm

Schematic — drawn from the table, not to scale for inspection.

SymbolItemValue
DOutside diameter851mm
CFlange thickness / blind thickness88.9mm
D2Raised face diameter711mm
fRaised face height6.4mm
KBolt circle diameter781mm
nNumber of bolt holes28pcs
dBolt hole diameter38.1mm
AHub diameter689mm
HHub length / overall length149mm
BWelding-end diameter660.4mm
—Approximate weight163kg

Pressure–temperature ratings · Class 400 · Group 1.1

≤ 38 °C68.0 bar50 °C66.4 bar100 °C62.3 bar150 °C60.1 bar200 °C58.4 bar250 °C56.0 bar300 °C53.2 bar325 °C51.6 bar350 °C50.2 bar375 °C48.5 bar400 °C46.2 bar425 °C38.3 bar450 °C30.6 bar475 °C23.3 bar500 °C15.4 bar538 °C7.7 bar

Source: Table 3 (p. 14) — pressure–temperature ratings for Group 1.1 materials, SI units; Group 1.1.

Material and notes

Base material: ASTM A105 (North America, Middle East)

Rating: Series B follows the former API 605 dimensions, with a smaller outside diameter and a different bolt pattern from Series A. Ratings are ASME classes 150, 300, 400, 600 and 900, with allowable pressure from the B16.47 tables.

Tolerances / marking: Tolerances, material and marking: ASME B16.47-2025. Series B and Series A are not interchangeable.

Notes / special requirements

Work order Inspector Date Travels with the part; file after inspection