German and former Soviet Union application standard system:

With China's opening-up to the outside world and its accession to the WTO, various industries have become increasingly interconnected with the international community. To better align with international standards, personnel engaged in pressure pipeline design are required to have an understanding of the commonly used and advanced standard systems in the international community. The following are several major application standard systems. 

a. Germany (DIN) 

◆ Pipe: Large outer diameter series 

◆Pipe flange: European style flange 

Pressure levels: PN0.1, 0.25, 0.6, 1.0, 1.6, 2.5, 4.0, 6.4, 10.0, 16.0, 25.0, 32.0, 40.0  - 13 levels 

Nominal diameter: DN6 to 4000mm 

Flange sealing surfaces: flat surface, raised platform surface, concave-convex surface, mortise-slot surface, rubber ring connection surface, lens surface and diaphragm welding surface, totaling 7 types. 

Flange type: Flat welding plate type, flat welding loose fitting type, flanging loose fitting type, butt welding flanging loose fitting type, butt welding ring flanging loose fitting type, butt welding type, threaded connection type, integral type and flange cover 9 types 

◆Common standards 

DIN2410.T.1 Pipe and Steel Pipe Standards Overview 

DIN2448 Seamless Steel Pipe - Dimensions and Mass per Unit Length 

DIN2458 welded steel pipe - Dimensions and unit length weight 

General Description of DIN2500 Flange 

DIN2501.T.1 Flange Connection Dimensions 

DIN2519 Steel Flange Delivery Technical Conditions 

Threaded steel pipe fittings in accordance with DIN2980 standard 

b. The former Soviet Union (GOC) 

◆Pipe: Small outer diameter series. The outer diameter size is the same as that of the JB series in China. 

◆Pipe flange: European style flange 

Pressure levels: PN 0.1, 0.25, 0.6, 1.0, 1.6, 2.5, 4.0, 6.4, 10.0, 16.0, 20.0 - 11 levels 

Nominal diameter: DN6 to 3000mm 

Flange sealing surfaces: 7 types including full plane, raised platform surface, concave-convex surface, polytetrafluoroethylene tenon groove surface, lens surface, and elliptical ring connection surface. 

Flange type: Flat welding plate type, flat welding loose fitting type, flanging loose fitting type, butt welding type, threaded connection type, integral type, and flange type, totaling 7 types. 

The German pipe flange standard DIN and the former Soviet Union pipe flange standard ΓOCT can be used in pairs within the PN ≤ 16.0 grade, but they cannot be interchanged (because the size series of the pipe fittings are different). With the disintegration of the former Soviet Union, the application standard system ΓOCT is currently rarely used in international engineering.