Overview
JIS B2220 specifies steel pipe flanges for the Japanese industrial system. It utilizes the "K" rating system (e.g., 5K, 10K, 20K) to designate pressure classes, representing the working pressure in kgf/cm² at ambient temperature.
Scope & Applicability
Applies To Industries
Covers — Japanese standard steel flanges:
- Sizes designated by A (e.g., 50A approx. NPS 2).
- Pressure ratings: 5K, 10K, 16K, 20K, 30K, 40K, 63K.
- Types: SOP (Slip-On Plate), SOH (Slip-On Hubbed), WN (Weld Neck), BL (Blind).
Does NOT cover (exclusions) — the following are governed elsewhere:
- ASME Class or EN PN flanges.
Key Requirements
JIS B2220 provides the dimensional and pressure framework for equipment made in Japan and widely used across Asia:
- Uses metric dimensions entirely.
- Integrates seamlessly with JIS standard piping (e.g., JIS G3452 SGP, JIS G3454 STPG).
Technical Details
In many Asian industrial facilities outside of the petrochemical sector (e.g., food and beverage, light manufacturing, water treatment), JIS B2220 10K flanges are the absolute standard.
Like EN flanges, JIS "K" flanges are geometrically incompatible with ASME B16.5 flanges.
Engineering Notes
A 10K flange has a working pressure of approximately 142 psi (10 kgf/cm²), putting it slightly below the capacity of an ASME Class 150 flange (285 psi). Do not mistake a JIS 20K flange as equivalent to a Class 150; their bolt circles are completely different.
Source, Edition & Status
- Publisher
- JIS
- Industries
- General Industry, Marine
- Last Reviewed
- 2026-07-01
- Last Updated
- 2026-07-01
- Verified By
- Engineering content reviewer
- Content Status
- reviewed