FLANGE STANDARD LIBRARYAX FORGE · SPEC SHEET
SPEC SHEETNo. 395
ASME B16.5 · ASME B16.5-2025

B16.5 Class 400 16″ Weld Neck

DN400Weld NeckDimensions mmWeight kg
ASME B16.5 · 16″ (DN400) · Class 400 · Weld Neck FlangeASME B16.5 · 16″ (DN400) · Class 400 · Weld Neck Flange O.D. D 647.7 Bolt circle K 571.5 20ר38.1 Raised face Ø 469.9 Thickness C 63.5 RF height f 6.4 Length H 152.4 Hub Ø A 482.6 Weld end Ø 406.4 Both views share one scale (1:10); schematic only Unit: mm

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

SymbolItemValue
DOutside diameter647.7mm
CFlange thickness / blind thickness63.5mm
D2Raised face diameter469.9mm
fRaised face height6.4mm
KBolt circle diameter571.5mm
nNumber of bolt holes20pcs
dBolt hole diameter38.1mm
AHub diameter482.6mm
HHub length / overall length152.4mm
BWelding-end diameter406.4mm
—Approximate weight134kg

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