FLANGE STANDARD LIBRARYAX FORGE · SPEC SHEET
SPEC SHEETNo. 453
ASME B16.5 · ASME B16.5-2025

B16.5 Class 1500 12″ Weld Neck

DN300Weld NeckDimensions mmWeight kg
ASME B16.5 · 12″ (DN300) · Class 1500 · Weld Neck FlangeASME B16.5 · 12″ (DN300) · Class 1500 · Weld Neck Flange O.D. D 673.1 Bolt circle K 571.5 16ר54.0 Raised face Ø 381.0 Thickness C 124.0 RF height f 6.4 Length H 282.4 Hub Ø A 450.9 Weld end Ø 323.9 Both views share one scale (1:19); schematic only Unit: mm

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

SymbolItemValue
DOutside diameter673.1mm
CFlange thickness / blind thickness124mm
D2Raised face diameter381mm
fRaised face height6.4mm
KBolt circle diameter571.5mm
nNumber of bolt holes16pcs
dBolt hole diameter54mm
AHub diameter450.9mm
HHub length / overall length282.4mm
BWelding-end diameter323.9mm
—Approximate weight313kg

Pressure–temperature ratings · Class 1500 · Group 1.1

≤ 38 °C255.1 bar50 °C248.9 bar100 °C233.5 bar150 °C225.3 bar200 °C219.1 bar250 °C209.8 bar300 °C199.5 bar325 °C193.4 bar350 °C188.2 bar375 °C182.1 bar400 °C173.1 bar425 °C143.7 bar450 °C114.9 bar475 °C87.4 bar500 °C57.6 bar538 °C29.0 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