1. Flange connection or flange joint refers to a detach […]
1. Flange connection or flange joint refers to a detachable connection that is connected by flanges, gaskets and bolts as a set of combined sealing structure. Pipeline flange refers to the flange used for piping in pipeline installations. Refers to the inlet and outlet flanges of the equipment on 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, 40.0Mpa
b. Common diameter: 15~2000mm
c. Flange structure type: flat welded plate, flat welded ring loose sleeve, crimped loose sleeve, butt welded crimped loose sleeve, butt welded loose sleeve, butt welded, threaded connection with neck, Integral type and flange cover
d. Flange sealing surface includes: flat surface, concave surface, concave-convex surface, tongue and groove surface, rubber ring connection surface, lens surface and diaphragm welding surface
e. The OCT pipe flange recording standard issued by the Soviet Union in 1980 is similar to the German DIN standard, so I won’t repeat it
2) American Flange System: American ANSI B16.5 "Steel Pipe Flanges and Flange Fittings" ANSI B16.47A/B "Large Diameter Steel Flanges"
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 diameter: 6~4000mm
c. Flange structure type: bar welding, socket welding, threaded connection, loose sleeve, butt welding and flange cover
d. Flange sealing surface: concave surface, concave-convex surface, tongue and groove surface, metal ring connection surface
3) ***JIS pipe flanges: Generally, they are only used in public works in petrochemical plants. They have little influence in the world, and there is no independent system in the world.
3. China 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, PN0.25, PN0.6, PN1.0, PN1.6, PN2.5, PN4.0 have a total of 6 grades of flange sizes belonging to the European flange system represented by German flanges, and the rest are American laws The American flange system represented by Lan.
In the GB standard, the maximum nominal pressure level of the European flange system is 40Mpa, and the maximum nominal pressure level of the American flange system is 42Mpa.
2) Nominal diameter: 10mm~1500mm
3) The structure of the flange:
a, threaded flange
b. Welding flange Butt welding flange
Flat welding flange with neck socket welding flange plate flat welding flange with neck
c. Loose flange, butt weld ring, loose sleeve flange with neck, butt weld ring, loose plate flange, flat weld ring, loose plate flange, plate flip over loose flange
d. Flange cover (blind hole flange)
e. Rotating flange
f. Anchor flange
g. Overlay welding/cover welding flange
4) Flange sealing surface: flat surface, concave surface, concave and convex surface, tongue and groove surface, ring connection surface