FLANGE STANDARD LIBRARYAX FORGE · SPEC SHEET
SPEC SHEETNo. 329
ASME B16.47 Series B · ASME B16.47-2025

B16.47 B Class 900 34″ Weld Neck

DN850Weld NeckDimensions mmWeight kg
ASME B16.47 Series B · 34″ (DN850) · Class 900 · Weld Neck FlangeASME B16.47 Series B · 34″ (DN850) · Class 900 · Weld Neck Flange O.D. D 1314.0 Bolt circle K 1155.7 20ר85.7 Raised face Ø 991.0 Thickness C 171.5 RF height f 6.4 Length H 319.0 Hub Ø A 962.0 Weld end Ø 863.6 Both views share one scale (1:21); schematic only Unit: mm

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

SymbolItemValue
DOutside diameter1314mm
CFlange thickness / blind thickness171.5mm
D2Raised face diameter991mm
fRaised face height6.4mm
KBolt circle diameter1155.7mm
nNumber of bolt holes20pcs
dBolt hole diameter85.7mm
AHub diameter962mm
HHub length / overall length319mm
BWelding-end diameter863.6mm
—Approximate weight1111kg

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 3 (p. 14) — pressure–temperature ratings for Group 1.1 materials, SI units; Group 1.1.

Material and notes

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

Rating: Series B follows the former API 605 dimensions, with a smaller outside diameter and a different bolt pattern from Series A. Ratings are ASME classes 150, 300, 400, 600 and 900, with allowable pressure from the B16.47 tables.

Tolerances / marking: Tolerances, material and marking: ASME B16.47-2025. Series B and Series A are not interchangeable.

Notes / special requirements

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