JIS B2220 (Steel Pipe Flanges — Japanese Standard)
Also known as: JIS flange · 5K flange · 10K flange · JIS B2220
JIS B2220 defines Japanese steel pipe flanges in pressure classes 5K, 10K, 16K, 20K, 30K, 40K, and 63K (kgf/cm²) — prevalent in Japanese-origin process equipment across Asian industrial plants.
Technical Detail
JIS B2220 (Steel pipe flanges) specifies flange dimensions for DN (nominal diameter) 10A to 1500A in seven pressure classes. Class designator K = kgf/cm² at 120°C reference temperature. Approximate MPa equivalents: 5K = 0.49 MPa, 10K = 0.98 MPa, 16K = 1.57 MPa, 20K = 1.96 MPa, 30K = 2.94 MPa, 40K = 3.92 MPa, 63K = 6.18 MPa. Most common in Vietnam: 10K (general process piping), 16K (process gas and steam), 20K–40K (boiler and high-pressure steam). Face type: Flat Face (FF) is the JIS default — requires full-face gaskets (covering entire flange face including bolt holes), unlike the raised-face ring gaskets common in DIN/ANSI flanges. Mating O-ring grooves on JIS flanges are defined in JIS B2404 (G-series O-rings, JIS B2401).
Reference Standards
- JIS B2220:2012
- JIS B2404
- JIS B2401
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