FLANGE STANDARD LIBRARYAX FORGE · SPEC SHEET
SPEC SHEETNo. 391
ASME B16.5 · ASME B16.5-2025

B16.5 Class 400 8″ Weld Neck

DN200Weld NeckDimensions mmWeight kg
ASME B16.5 · 8″ (DN200) · Class 400 · Weld Neck FlangeASME B16.5 · 8″ (DN200) · Class 400 · Weld Neck Flange O.D. D 381.0 Bolt circle K 330.2 12ר28.6 Raised face Ø 269.7 Thickness C 47.8 RF height f 6.4 Length H 117.3 Hub Ø A 260.4 Weld end Ø 219.2 Both views share one scale (1:6.7); schematic only Unit: mm

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

SymbolItemValue
DOutside diameter381mm
CFlange thickness / blind thickness47.8mm
D2Raised face diameter269.7mm
fRaised face height6.4mm
KBolt circle diameter330.2mm
nNumber of bolt holes12pcs
dBolt hole diameter28.6mm
AHub diameter260.4mm
HHub length / overall length117.3mm
BWelding-end diameter219.2mm
—Approximate weight40.4kg

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 2-1.1 (printed p. 25) — pressure–temperature ratings for Group 1.1 materials, SI units; Group 1.1.

Material and notes

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

Rating: ASME classes are not fixed pressures. For ASTM A105 (material group 1.1) the ASME B16.5-2025 ambient rating is 285 psi (19.6 bar) at Class 150, 740 psi (51.0 bar) at Class 300, 985 psi (68.0 bar) at Class 400, 1,480 psi (102.0 bar) at Class 600, 2,2…

Tolerances / marking: Tolerances, facing finish, material and marking requirements: ASME B16.5-2025 Sections 6 and 7.

Notes / special requirements

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