Japanese Flange Application Standard (JIS)

Nominal diameter: DN10~DN1000mm
Pressure level: 8 levels of IOK, 16K, 20K, 30K, 40K, 63K
Flange sealing surface: 5 types: smooth surface, large convex surface, small convex surface, concave and convex surface, tongue and groove surface
Flange type: flat welding (SO), socket welding (SW), butt welding (WN), threaded connection (TH), loose sleeve and flange cover (BL), etc.
Example 1: JIS 21/2 10K flange
JIS Japanese flange standard, 2-1/2 is the international size called NPS; my country is called DN, 65, 10K is the Japanese standard kilogram pressure.
To be accurate: DN65, NPS2-1/2, flange outer diameter 175, inner diameter 77.1 (with steel pipe diameter 76), thickness 18, center circle diameter 140, bolt hole number 4, bolt hole diameter 19, bolt M16, flange approximate The weight is 2.58 kg.
Example 2: JIS 10K SO 1B (RF) flange
JIS Japanese flange standard, 10K should be the pressure resistance, SO is flat welding flange, (RF) means the sealing surface type is convex, 1B is 1 inch is 1 inch pipe.
Note: MPa is usually used in my country, but in the United States, Britain and some European countries, the pressure level (CL) in English units is still used in practical applications, and the “K” level system is implemented in Japanese standards, such as 10K, 20K, etc. The concept of this pressure level system is the same as that of the British pressure level system, but the unit of measurement is the metric system; because the nominal pressure and the temperature reference of the pressure level are different, there is no strict correspondence between the three. The approximate correspondence is:
CL: 150, 300, 400, 600, 900
K level: 10, 20, 30, 45, 65
Nominal pressure PN/MPa: 2.0, 5.0, 6.8, 11.0, 15.0
JIS 10K about 1.37MPa
JIS 20K about 3.33MPa JIS 30K about 4.99MPa JIS 40K about 6.66MPa PN16=1.6MPA
PN64=6.4MPA


Post time: Apr-18-2022