FLANGE STANDARD LIBRARYAX FORGE · SPEC SHEET
SPEC SHEETNo. 671
ASME B16.5 · ASME B16.5-2025

B16.5 Class 900 1½″ Blind

DN40BlindDimensions mmWeight kg
ASME B16.5 · 1½″ (DN40) · Class 900 · Blind FlangeASME B16.5 · 1½″ (DN40) · Class 900 · Blind Flange O.D. D 177.8 Bolt circle K 124.0 4ר28.6 Raised face Ø 73.2 Thickness C 31.8 RF height f 6.4 Both views share one scale (1:2.8); schematic only Unit: mm

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

SymbolItemValue
DOutside diameter177.8mm
CFlange thickness / blind thickness31.8mm
D2Raised face diameter73.2mm
fRaised face height6.4mm
KBolt circle diameter124mm
nNumber of bolt holes4pcs
dBolt hole diameter28.6mm
—Approximate weight5.9kg

Pressure–temperature ratings · Class 900 · Group 1.1

≤ 38 °C153.1 bar50 °C149.3 bar100 °C140.1 bar150 °C135.2 bar200 °C131.5 bar250 °C125.9 bar300 °C119.7 bar325 °C116.0 bar350 °C112.9 bar375 °C109.2 bar400 °C103.9 bar425 °C86.2 bar450 °C68.9 bar475 °C52.5 bar500 °C34.6 bar538 °C17.4 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