American system flange(ansi/asme) and European System flange(din/uni)

International flange standards are divided into 3 types: European flange system (Germany flange DIN), American Standard flange system (American National Standards Institute ANSI B16.5 Steel Pipe Flanges and Flanged Fittings), and Japanese Standard flange system, JIS /KS Flange etc.

ANSI flanges (ANSI) pressure rating: Class 150 300 400 600 900 1500 2500, which unit is lbf/in2. The corresponding Pressure rating PN 2.0, 5.0, 6.8, 10.0, 15.0, 25.0, 42.0 MPa

European standard flange (DIN) pressure rating: the PN 0.1 0.25 0.6 1.0 1.6 2.5 4.0 6.3 10.0 16.0 25.0 40.0 MPa, which unit is kgf/MM2.

European standard system American Standard system either flange or pipe can not be mixed.

American National Standard ANSI B16.5 Steel pipe flanges and flanged fittings, is a more mature, more complete, more popular generic international advanced standard. American Standard ANSI B16.5 and other related ANSI, ASTM, API, the MSS pressure pipe applications standard system formed in a research trial basis, has decades of practice tests, a state-of-the-art, scientific standard, widely accepted by other countries of the world.

With the disintegration of the former Soviet Union, the application of standard system ΓOCT international engineering has been rarely used. The former Soviet Union the tube the flange standard ΓOCT and German standard DIN flanges in PN �16.0 level can be paired to use, but because over size series is not interchangeable.