Several systems of international pipe flange standards

1. Flange connection or flange joint refers to a foldable connection in which flanges, gaskets and bolts are connected to each other as a set of combined sealing structures. Pipe flanges refer to flanges used for piping in pipeline installations. On equipment, it refers to the inlet and outlet flanges of the equipment.

2. Several systems of international pipe flange standards

1) European flange system: German DIN (including the Soviet Union)

a. Nominal pressure: 0.1, 0.25, 0.6, 1.0, 1.6, 2.5, 4.0, 6.4, 10.0, 16.0, 25.0, 32.0, 40.0, Mpa

b. Calculated diameter: 15~600mm

c. Flange structure type: flat welding plate type, flat welding ring loose sleeve type, crimping loose sleeve type, butt welding crimping loose sleeve type, butt welding ring loose sleeve type, butt welding type, neck thread connection type, Integral and Flange Covers

d. The flange sealing surface includes: plane, concave, concave and convex surface, tenon and groove surface, rubber ring connection surface, lens surface and diaphragm welding surface

e. The OCT pipe flange compendium standard issued by the Soviet Union in 1980 is similar to the German DIN standard and will not be repeated

2) American flange system: American ANSI B16.5 "Steel Pipe Flanges and Flange Fittings"

a. Nominal pressure: 150psi (2.0Mpa), 300psi (5.0Mpa), 400psi (6.8Mpa), 600psi (10.0Mpa), 900psi (15.0Mpa), 1500psi (25.0Mpa), 2500psi (42.0Mpa),

b. Calculated diameter: 6~4000mm

c. Structural type of flange: strip welding, socket welding, threaded connection, loose sleeve, butt welding and flange cover

d. Flange sealing surface: concave surface, concave-convex surface, tongue groove surface, metal ring connection surface

3) ***JIS pipe flange: It is generally only used for public works in petrochemical plants, and has little influence in the world, and there is no independent system in the world.

3. my country's national standard system for steel pipe flanges GB

1) Nominal pressure: 0.25Mpa~42.0Mpa

a. Series 1: PN1.0, PN1.6, PN2.0, PN5.0, PN10.0, PN15.0, PN25.0, PN42 (main series)

b. Series 2: PN0.25, PN0.6, PN2.5, PN4.0

Among them, the flange sizes of 6 grades of PN0.25, PN0.6, PN1.0, PN1.6, PN2.5 and PN4.0 belong to the European flange system represented by German flanges, and the rest are American flanges. The American flange system represented by blue.

In the GB standard, the maximum nominal pressure level belonging to the European flange system is 4Mpa, and the maximum nominal pressure level belonging to the American flange system is 42Mpa.

2) Nominal diameter: 10mm~4000mm

3) The structure of the flange:

Integral flange

unit flange

a. Threaded flange

b. Welding flange butt welding flange

Flat Welding Flange with Neck Socket Welding Flange Plate Flat Welding Flange

c. Loose sleeve flange butt welding ring loose sleeve with neck flange butt welding ring loose sleeve plate flange flat welding ring loose sleeve plate flange plate type over loose flange

d. Flange cover (blind hole flange)

4) Flange sealing surface: flat surface, concave surface, concave-convex surface, tongue groove surface, ring connection surface

2. Standard system of pipe flanges commonly used in instruments

1. DIN standard

1) Common pressure grades: PN6, PN10, PN16, PN25, PN40, PN64, PN100, PN160, PN250

2) Flange sealing surface: raised face DIN2526C raised face flange grooued acc. DIN2512N tongue and groove face

2. ANSI standard

1) Common pressure grades: CL150, CL300, CL600, CL900, CL1500

2) Flange sealing surface: ANSI B 16.5 RF flanges

3. JIS standard: not commonly used

1) Common pressure level: 10K, 20K