High And Low Pressure Flat Welding Flange National Standard With Diameter Butt Welding Flange

1. Flange connection or flange joint refers to the detachable connection which is connected by flange, gasket and bolt as a group of assembled sealing structure. Pipe flange refers to the flange with pipe in the pipeline device, and refers to the import and export flange of the equipment when used in the equipment.
2. Several systems of international pipe flange standards
1) European flange system: German DIN (including Russia)
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. Common calculation diameter: 15~2000mm
C, flange structure type: flat welding plate, flat welding ring loose sleeve type, roll edge loose sleeve type, roll edge loose sleeve type, welding ring loose sleeve type, welding type, neck thread connection type, integral and flange cover
D, flange sealing surface: flat surface, concave surface, concave surface, tenon groove surface, rubber ring connection surface, lens surface and diaphragm welding surface
E. The Co-recording standard for OCT pipe flanges issued by the Soviet Union in 1980 is similar to the German DIN standard and will not be described in detail
2) American flange system: American ANSI B16.5 "Steel pipe flanges and flanged pipe fittings" ANSI B16.47A/B "Large Diameter Steel flange"
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. Common calculation diameter: 6~4000mm
C, flange structure type: strip welding, socket welding, thread connection, loose sleeve, butt welding and flange cover
D, flange sealing surface: concave surface, concave surface, tenon groove surface, metal ring connection surface
3) ***JIS pipe flanges: generally only used for public works in petrochemical installations, with little international influence and no independent system in the world.
3, China's steel pipe flange national standard system 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
The flanges of PN0.25, PN0.6, PN1.0, PN1.6, PN2.5 and PN4.0 belong to the European flanges system represented by German flanges, while the rest belong to the American flanges system represented by American flanges.
In GB standard, the maximum nominal pressure level belonging to the European flange system is 40Mpa, the maximum nominal pressure level belonging to the American flange system is 42Mpa.
2) Nominal diameter: 10mm~1500mm
3) Flange structure:
Integral flange
Unit of the flange
A. Threaded flange
Welding flanges butt welding flanges
Flat welding flange with neck socket welding flange plate welding flange
C. Loose flange butt welding ring loose sleeve neck flange butt welding ring loose sleeve plate flange flat welding ring loose sleeve plate flange flip loose sleeve flange
D. Flange cover (blind hole flange)
E. Rotating flange
F. Anchorage flange
G. Surfacing/cladding flange