JIS B2220 is the Japanese Industrial Standard for steel pipe flanges, widely used in Japan, Southeast Asia, and internationally in equipment sourced from Japanese manufacturers. The standard uses a K-class pressure system (5K, 10K, 16K, 20K, 30K, 40K, 63K) and covers pipe sizes from DN 10 (3/8") to DN 1500 (60"). JIS B2220 flanges are commonly specified in petrochemical plants, refineries, and industrial facilities across Asia-Pacific.
JIS B2220 — Japanese Steel Flange Standard 5K – 63K
JIS B2220 is the Japanese Industrial Standard for steel pipe flanges, widely used in Japan, Southeast Asia, and internationally in equipment sourced from Japanese manufacturers. Covers DN 10 (3/8") to DN 1500 (60") across pressure classes 5K to 63K.
Key Specifications
Standard: JIS B2220:2012
Pressure Classes: 5K / 10K / 16K / 20K / 30K / 40K / 63K
Size Range: DN 10 (3/8") – DN 1500 (60")
Face Types: Flat Face (FF), Raised Face (RF), Ring Type Joint (RTJ)
Flange Types: Weld Neck (WN), Slip-On (SO), Blind (BL), Socket Weld (SW), Threaded (TH), Lap Joint (LJ)
Facing Standard: JIS B 2202
Pressure Class vs. Approximate PN/ANSI Equivalent
| JIS Class |
Max Pressure (kPa) |
Max Pressure (bar) |
ANSI Equivalent |
Typical Service |
| 5K |
490 kPa |
~5 bar |
~PN 5 / Class 150 |
Low-pressure water, drainage, HVAC |
| 10K |
980 kPa |
~10 bar |
~PN 10 / Class 150 |
General industrial water, steam |
| 16K |
1,570 kPa |
~16 bar |
~PN 16 / Class 300 |
Medium-pressure steam, oil lines |
| 20K |
1,960 kPa |
~20 bar |
~PN 20 / Class 300 |
Higher-pressure process lines |
| 30K |
2,940 kPa |
~30 bar |
~PN 25 / Class 600 |
High-pressure steam, gas |
| 40K |
3,920 kPa |
~40 bar |
~PN 40 / Class 600 |
Power plant, high-pressure |
| 63K |
6,170 kPa |
~63 bar |
~PN 63 / Class 900 |
Ultra-high pressure |
Table 1: JIS B2220 pressure class (K) vs. approximate PN and ANSI equivalents. Actual pressure-temperature ratings per JIS B2220:2012 tables.
JIS B2220 — Raised Face Dimensions (g and f) — Selected Sizes
| DN |
5K |
10K |
16K |
20K |
30K |
| g (mm) |
f (mm) |
g (mm) |
f (mm) |
g (mm) |
f (mm) |
g (mm) |
f (mm) |
g (mm) |
f (mm) |
| 10 |
39 |
1 |
46 |
1 |
46 |
1 |
46 |
1 |
52 |
1 |
| 15 |
44 |
1 |
51 |
1 |
51 |
1 |
51 |
1 |
55 |
1 |
| 25 |
59 |
1 |
67 |
1 |
67 |
1 |
67 |
1 |
70 |
1 |
| 40 |
75 |
2 |
81 |
2 |
81 |
2 |
81 |
2 |
90 |
2 |
| 50 |
85 |
2 |
96 |
2 |
96 |
2 |
96 |
2 |
105 |
2 |
| 80 |
121 |
2 |
126 |
2 |
132 |
2 |
132 |
2 |
140 |
2 |
| 100 |
141 |
2 |
151 |
2 |
160 |
2 |
160 |
2 |
160 |
2 |
| 150 |
206 |
2 |
212 |
2 |
230 |
2 |
230 |
2 |
235 |
2 |
| 200 |
252 |
2 |
262 |
2 |
275 |
2 |
275 |
2 |
280 |
2 |
| 300 |
360 |
3 |
368 |
3 |
395 |
3 |
395 |
3 |
405 |
3 |
| 400 |
463 |
3 |
475 |
3 |
495 |
3 |
495 |
3 |
510 |
3 |
| 500 |
573 |
3 |
585 |
3 |
615 |
3 |
615 |
3 |
— |
— |
| 600 |
680 |
3 |
690 |
3 |
720 |
3 |
720 |
3 |
— |
— |
Table 2: JIS B2220 Raised Face (RF) dimensions — g (gasket/seat diameter) and f (RF height). Values per JIS B2220:2012 / JIS B 2202 facing standard.
JIS B2220 Flange Types
| Type Code |
Full Name |
Application |
| WN |
Weld Neck |
High-pressure, high-temperature, cyclic service |
| SO |
Slip-On |
Lower pressure, easy assembly |
| BL |
Blind |
System closure, isolation |
| SW |
Socket Weld |
Small bore, high-pressure |
| TH |
Threaded |
No-weld assembly |
| LJ |
Lap Joint |
Corrosion-resistant, frequent disassembly |
Table 3: JIS B2220 flange type codes and their applications.
JIS B2220 Materials
Carbon Steel (Forged): JIS S25C, SS400, SFVC2A (A105 equivalent)
Carbon Steel (Plate): JIS SM400, SM490, SPV235
Stainless Steel: JIS SUS304, SUS304L, SUS316, SUS316L, CF8, CF8M (ASTM A351)
Duplex: SUS329J3, SUS329J4 (equivalent to S31803)
Alloy Steel: JIS SCM415, SCM435, SCPH2 (2¼Cr-1Mo)
Inconel/Monel: NCF600, NCF625, NCu30 (on request)
Applications
Japanese-manufactured plant and process equipment
Oil refineries and petrochemical complexes in Asia-Pacific
Marine and offshore installations (JIS marine class)
Industrial boiler and pressure vessel connections
Water treatment and desalination plants
Power generation (30K–63K classes)
Flange Material Selection Guide
| Material |
Grade |
Max Temp |
Key Application |
| Carbon Steel |
SFVC2A / A105 |
425°C |
Steam, water, air, oil |
| Stainless Steel 316 |
SUS316 / A182 F316 |
400°C |
Chemical, food, pharma |
| Stainless Steel 316L |
SUS316L / A182 F316L |
400°C |
Weld-intensive fabrication |
| Duplex |
SUS329J3 / S31803 |
300°C |
Offshore, seawater |
| Alloy Steel SCPH2 |
2¼Cr-1Mo |
550°C |
Power plant, refineries |
Table 4: Material selection guide for JIS B2220 flanges.
HT PIPE manufactures JIS B2220 flanges in all types (WN, SO, BL, SW, TH, LJ) in carbon steel, stainless steel, and special alloys. All flanges supplied with material test reports and dimensional inspection certificates.
