FLANGE STANDARD LIBRARYAX FORGE · SPEC SHEET
SPEC SHEETNo. 1205
JIS B2220 · JIS B2220:2012

JIS B2220 16K 250A Weld Neck

DN250Weld NeckDimensions mmWeight kg
JIS B2220 · 250A (DN250) · 16K · Weld Neck FlangeJIS B2220 · 250A (DN250) · 16K · Weld Neck Flange O.D. D 430.0 Bolt circle K 380.0 12ר27.0 Raised face Ø 345.0 Thickness C 28.0 RF height f 2.0 No hub data Both views share one scale (1:6.8); schematic only Unit: mm

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

SymbolItemValue
DOutside diameter430mm
CFlange thickness / blind thickness28mm
D2Raised face diameter345mm
fRaised face height2mm
KBolt circle diameter380mm
nNumber of bolt holes12pcs
dBolt hole diameter27mm
HHub length / overall length81mm

Pressure–temperature ratings · 16K · Group 1.1

≤ 120 °C2.7 MPa220 °C2.5 MPa300 °C2.3 MPa350 °C2.1 MPa400 °C1.8 a) MPa425 °C1.6 a) MPa

Source: Table 11 (pp. 15–16) — pressure-temperature rating, maximum working pressure in MPa; Group 1.1.

Material and notes

Base material: SS400 / S25C (Japan, Korea, South-East Asia, marine and shipbuilding)

Rating: JIS K ratings are kgf/cm² nominal: 5K ≈ 0.5 MPa, 10K ≈ 1.0 MPa, 16K ≈ 1.6 MPa, 20K ≈ 2.0 MPa and 30K ≈ 3.0 MPa. The published maximum working pressure is higher or lower than the nominal figure depending on material group and division — for material…

Tolerances / marking: Tolerances, material groups and marking: JIS B2220:2012, including Table 11.

Notes / special requirements

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