FLANGE STANDARD LIBRARYAX FORGE · SPEC SHEET
SPEC SHEETNo. 369
ASME B16.5 · ASME B16.5-2025

B16.5 Class 300 6″ Weld Neck

DN150Weld NeckDimensions mmWeight kg
ASME B16.5 · 6″ (DN150) · Class 300 · Weld Neck FlangeASME B16.5 · 6″ (DN150) · Class 300 · Weld Neck Flange O.D. D 317.5 Bolt circle K 269.7 12ר22.2 Raised face Ø 215.9 Thickness C 35.1 RF height f 1.5 Length H 97.0 Hub Ø A 206.2 Weld end Ø 168.4 Both views share one scale (1:5.5); schematic only Unit: mm

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

SymbolItemValue
DOutside diameter317.5mm
CFlange thickness / blind thickness35.1mm
D2Raised face diameter215.9mm
fRaised face height1.5mm
KBolt circle diameter269.7mm
nNumber of bolt holes12pcs
dBolt hole diameter22.2mm
AHub diameter206.2mm
HHub length / overall length97mm
BWelding-end diameter168.4mm
—Approximate weight19.1kg

Pressure–temperature ratings · Class 300 · Group 1.1

≤ 38 °C51.0 bar50 °C49.8 bar100 °C46.7 bar150 °C45.1 bar200 °C43.8 bar250 °C42.0 bar300 °C39.9 bar325 °C38.7 bar350 °C37.6 bar375 °C36.4 bar400 °C34.6 bar425 °C28.7 bar450 °C23.0 bar475 °C17.5 bar500 °C11.5 bar538 °C5.8 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