Detailed introduction of the hottest flange

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Detailed introduction of flange

flange this section of high pressure flange (SAE flange jbzq)

is also called flange or flange

parts that connect pipes to each other are connected to the pipe end. There are holes on the flange, and the bolts make the two flanges tightly connected. The flanges are sealed with gaskets. Flanged pipe fittings refer to pipe fittings with flanges (lugs or adapters). It can be cast (not shown in the figure), or it can be formed by threaded connection or welding. Flange, joint is composed of a pair of flanges, a gasket and several bolts and nuts. The gasket is placed between the two flange sealing faces. After tightening the nut, the specific pressure on the gasket surface reaches a certain value and deforms, and the uneven parts on the sealing face are filled to make the connection tight. Flange connection is a detachable connection. According to the connected parts, it can be divided into container flange and pipe flange. According to the structural type, there are integral flange, looper flange and threaded flange. Common integral flanges include flat welding flanges and butt welding flanges. The flat welding flange has poor rigidity and is suitable for occasions with pressure P ≤ 4MPa; Butt welding flange, also known as high neck flange, is rigid and suitable for occasions with high pressure and temperature. There are three types of flange sealing surface: plane sealing surface, which is suitable for occasions with low pressure and non-toxic medium; Concave convex sealing surface, suitable for occasions with slightly higher pressure; Tenon and groove sealing surface is suitable for flammable, explosive, toxic media and high pressure occasions. Gasket is a kind of ring made of material that can produce plastic deformation and has certain strength. Most of the gaskets are cut from non-metallic plates or made by professional factories according to the specified size, and their materials are asbestos rubber plates, asbestos plates, polyethylene plates, etc; There are also metal clad gaskets made by wrapping asbestos and other non-metallic materials with thin metal plates (white iron sheet, stainless steel); There is also a spiral wound gasket made of thin steel tape and asbestos tape. Ordinary rubber gasket is suitable for occasions with temperature lower than 120 ℃; Asbestos rubber gasket is applicable to the occasions where the water vapor temperature is lower than 450 ℃, the oil temperature is lower than 350 ℃, and the pressure is lower than 5MPa. For general corrosive media, the most commonly used is acid resistant asbestos board. In high-pressure equipment and pipelines, metal gaskets of lens type or other shapes made of copper, aluminum, No. 10 steel and stainless steel are used. The contact width between the high-pressure gasket and the sealing surface is very narrow (line contact), and the processing finish of the sealing surface and gasket is high

flanges are divided into threaded (threaded) flanges and welded flanges. Low pressure small diameter threaded flange, high pressure and low pressure large diameter are welded flanges, and the thickness of flange plates and the diameter and number of connecting bolts under different pressures are different

according to different pressure levels, flange gaskets also have different materials, from low-pressure asbestos gasket, high-pressure asbestos gasket to metal gasket

1. Carbon steel, cast steel, alloy steel, stainless steel, copper, aluminum alloy, plastic, argon, PPC, etc. are divided by material

2. According to the manufacturing method, it can be divided into forged flange, cast flange, welded flange, rolled flange (super large model)

3 According to the manufacturing standards, it can be divided into national standards (standards of the Ministry of chemical industry, petroleum standards, electric power standards that make manufacturers dare not produce unqualified products), American standards, German standards, Japanese standards, Russian standards, etc

several systems of international pipe flange standards

1. Flange connection or flange joint refers to the foldable connection of flange, gasket and bolt as a group of combined sealing structure. Pipeline flange refers to the flange used for piping in pipeline devices, and refers to the inlet and outlet flanges of equipment when used on 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, common diameter: 15~600mm

c, flange structure type: flat welding plate, flat welding ring loose sleeve, crimping loose sleeve, butt welding.Welding curling loose sleeve type, butt welding ring loose sleeve type, butt welding type Threaded connection with neck, integral type and flange cover

d, flange sealing surfaces include: plane, concave, concave convex, tenon and groove surface, rubber ring connection surface, lens surface and diaphragm welding surface

e, the same record standard of OCT pipe flange issued by the Soviet Union in 1980 is similar to the German DIN standard, and it is no longer recalled

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), 600 psi (10.0MPa), 900psi (15.0mpa), 1500psi (25.0mpa), 2500psi (42.0mpa),

b, common 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 and convex surface, tenon and groove surface Metal ring connection surface

3) * **jis pipe flange: generally used in petrochemical plants only for public works, has little impact internationally, and has not formed an independent system internationally

3. China'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, pn0.25, pn0.6, PN1.0, pn1.6 the flange sizes of six grades, pn2.5 and pn4.0, belong to the European flange system represented by German flanges, The rest are American flange system represented by American flange

in the GB standard, the maximum nominal pressure class belonging to the European flange system is 4MPa, and the maximum nominal pressure class belonging to the American flange system is 42MPa

2) nominal diameter: 10mm~4000mm

3) structural form of flange:

integral flange

unit flange

A, threaded flange

b, welding flange butt welding flange

neck socket welding flange plate type flat welding flange

C, loose sleeve flange butt welding ring loose sleeve flange butt welding ring loose sleeve plate flange flat welding ring loose sleeve plate flange plate over loose sleeve flange

d, flange cover(blind flange)

e Rotating flange

f, anchor flange

g, surfacing/overlaying flange

4) flange sealing surface: plane, concave, convex, grooved surface, ring connection surface

II. Pipe flange standard system 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 grouted acc. din2512n tongue and groove surface

2, ANSI standard

1) common pressure grade: cl150, cl300, cl600, cl900, cl1500

2) flange sealing surface: ANSI B 16.5 RF flanges raised face flange

3, JIS standard: not commonly used

1) common pressure grade: 10K, 20K

flange connection type

plate type flat welding flange

necked flat welding flange

necked butt welding flange

socket welding flange

threaded flange

flange cover

loose flange with neck butt welding ring

loose flange with flat welding ring

ring groove face flange and flange cover

large diameter flat flange

large diameter high neck flange

spectacle blind plate

butt welding ring loose flange

rotating flange

anchor flange

surfacing/overlay welding flange flange connection in this section, the flange connection is to fix two pipes, pipe fittings or devices. 1) the mechanical resonance material of Jinan experimental machine is first fixed on a flange respectively, and the connection is completed by adding flange pads between the two flanges and fastening them together with bolts. Some pipe fittings and equipment have their own flanges, which also belong to flange connection. Flange connection is an important connection method in pipeline construction

flange connection is convenient to use and can withstand large pressure. Flange connection is widely used in industrial pipelines. In the family, the pipe diameter is small, and it is low-pressure, so the flange connection cannot be seen. If you are in a boiler room or production site, there are flanged pipes and equipment everywhere. Flange production standards should be verified in periodic verification if there is a need for detection. National standard of this section: gb/t (gb9113 · ~ gb9123?) American Standard: ANSI B16.5 class150, 300, 600, 900, 1500 (WN, so, BL, th, LJ, SW) Japanese standard: JIS 5K, 10K, 16K, 20K (PL, so, BL, WN, th, SW) German standard: din2573, 2572, 2631, 2576, 2632, 2633, 2543, 2634, 2545 (PL, so, WN, BL, th) Ministry of chemical industry standard: Hg ~ Hg, HGJ ~ HGJ, Hg series, Hg series machinery department standard: JB ~ JB, JB jb/t ~ jb/t, jb/t Pressure Vessel Standards: JB ~ JB JB ~ JB b16.47a/b b16.39 b16.48

flange ring: flange ring is a gasket. Many bearings used in light industry are called flanges for shock absorption and wear prevention. The flange used for toilet is placed between the sewage outlet and the water hole in the toilet, which plays a sealing role. In that way, the siphon toilet has no ventilation, and the flushing effect is better

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