ANSI B16.5 150# 300# 600# WELD NECK FLANGE


Carbon steel flange, the main material is carbon steel. Carbon steel flanges can be used with pipes for easily assembling and disassembling.

Carbon Steel materials for flanges: A105 steel, Q235B steel, A3 steel, 10# steel, 20# steel, 16Mn steel, 45# steel, Q345B steel

Machinery Department standard: JB/T81-94, JB/T79.4-94, JB/T83-94
Chemical Department standard: HG20593-97 / HG20617-97
National Standard: GB/T9119-2010
Marine Standard: CB M1001-81
Sealing and Pad for flanges: CB M1002-81
Thermal Powder Standard: D-GD87-1101
National Building Standard: S02403
European Standard: EN14420-2
American Flange Standard: ANSI B 16.5

PN pressure rating(12 kinds): PN2.5;PN6;PN10;PN16;PN25;PN40;PN63;PN100;PN160;PN250;PN320;PN400

Class pressure rating(6 kinds): Class 150;Class 300;Class 600;Class 900;Class 1500;Class 2500

Great for you

Carbon steel flanges are designed to have standard dimensions. Common world standards include ASA/ANSI/ASME (USA), PN/DIN (European), BS10 (British/Australian), and JIS/KS (Japanese/Korean).

Carbon steel flange faces are also made to standardiz dimensions and are typically “flat face”, “raised face”, “tongue and groove”, or “ring joint” styles, although other obscure styles are possible.

Carbon steel flange designs: Weld neck flange (WN flange), slip-on flange(SO flange), lap joint flange(LJ flange), socket weld flange(SW flange), threaded flange(TH flange), blind flange(BL flange).


Flanges are connected to each other between the tube and pipe parts, the connection between the pipe end for; also useful for equipment import and export on the flange for connection between two devices, such as a gear flange. Flange connection or flange joints, is defined by the flanges, gaskets and bolts are connected to each of the three combinations as a detachable connection seal structure. Pipe flange means piping means for piping flange, with import and export flange on equipment means equipment. There are holes on the flange, so that the two flange bolts tightly connected. Between flange sealing gasket. Flange threaded connection points (threaded connection) flanges, welded flanges and clip flange. Flanges are used in pairs, you can use low-pressure pipe thread flange, four kilograms more than the use of pressure welding flanges. Between the two flange gaskets, then bolted. Different flange thickness at different pressures, bolts they use is also different. Pumps and valves, and pipe connections at local these facilities and equipment, also made of a shape corresponding to the flange, also known as the flange connection. Any use of the surrounding bolted in two planes simultaneously closed parts, generally referred to as “flange”, such as ventilation pipe connections, this type of parts can be called “flange parts.” But this is only a partial connection device, such as flanges and pump connection, bad water pump called “flange parts.” Relatively small, such as valves, etc., can be called “flange parts.”

Reducer flange for connection to the motor and gearhead connection, as well as gear and other devices.

Chinese name English name Flange Type Flange mechanical parts Material stainless steel, carbon steel, nickel steel etc. Scope construction, heavy industry, plumbing, electricity and other international and domestic classification classification level by HG, SK, JB and GB standard classification

table of Contents

1 Classification

2 Material

3 connections

4 welding quality

5 Welding Technology

▪ required equipment

▪ preparation before welding

▪ welding process

▪ weld quality

▪ Caution

▪ flange gasket

6 related species

▪ Reducing flange

▪ Stainless steel flange

▪ pressure vessel flange

▪ flat welding flange

▪ weld neck (WN)

▪ socket welding flange (SW)

▪ threaded flange (TH)

▪ loose flanges

▪ high temperature flange seal

7 production standards

8 standard system

9 Production Process

10 Troubleshooting

11 metrics

▪ Technical conditions

▪ processing professional equipment

12 Scope


Plate flat welding steel pipe flanges

Plate flat welding steel pipe flanges

1, according to the chemical (HG) industry standard points: integral flange (IF), threaded flange (Th), plate flat welding flange (PL), with neck butt flange (WN), with neck flat welding flange (SO), socket welding flange (SW), welded ring loose flange (PJ / SE), flat welding ring loose flange (PJ / RJ), lining flange cover (BL (S)), flange cover (BL).

2, according to Sinopec (SH) industry standard scores: threaded flange (PT), welded flange (WN), flat welding flange (SO), socket welding flange (SW), loose flange (LJ) flange cover (not table note).

3. Press Machinery (JB) industry standard points: the overall flange, welded flange, welded flange plate, welded ring loose flange plate, flat plate welding ring loose flange, Loose plate flange ring flange, flange cover.

4, according to the national (GB) standard points: the overall flange, threaded flange, welded flange, with neck flat welding flange, with neck socket welding flange, welded neck collar with loose flange, plate flat welded flange, welded ring loose flange plate, flat plate welding ring loose flange, plate flange ring loose flange, flange cover.


Stainless steel welded steel pipe flanges with neck

Stainless steel welded steel pipe flanges with neck

WCB (Carbon), LCB (low carbon steel), LC3 (3.5% nickel steel), WC5 (1.25% Cr 0.5% Mo steel), WC9 (2.25% chromium), C5 (5% Cr 0.5% Mo), C12 (9% Cr 1% Mo), CA6NM (4 (12% chromium steel), CA15 (4) (12% chromium), CF8M (316 stainless steel), CF8C (347 stainless steel), CF8 (304 stainless steel), CF3 (304L stainless steel), CF3M (316L stainless steel), CN7M (steel), M35-1 (Monel), N7M (Haast nickel alloy B), CW6M (Hasta nickel alloy C), CY40 (Inconel) Wait.


Plate flat welding steel pipe flanges sheet

Plate flat welding steel pipe flanges sheet

Flange (flange) connection is the two pipes, fittings or equipment, first on their fixed in a flange between two flanges, plus flange pad, fastened together with bolts to complete the connection . Some fittings and equipment already comes with flange, also belong to the flange connection. Flanged connections are important pipeline construction. Flanged easy to use, able to withstand greater pressure. In the industrial pipeline, using a wide range of flange connection. Within the family, the pipe diameter is small, and is a low pressure, invisible flange connection. If in a boiler room or a production site, full of flanged pipe and equipment.

1, in accordance with the connection flange connection types can be divided into: plate flat welding flange, with neck flat welding flange, with neck flange, socket welding flange, threaded flange, flange cover with neck for welding ring loose flange, flat welding ring loose flange ring groove flange and flange cover, large-diameter flat flanges, large diameter high-neck flange, blind character, loose flange welded ring, etc. .

Welding Quality

As iron welded flanges, the quality of many customer questions is whether iron welded flanges than forged welding flanges. In fact, the quality of the welding flange quality iron and forged welded flange is the same, but in the end what iron welding flange can not secure it, which is the most iron welding flange material insecurity, because Usually the process, the density of iron welded flange is not a problem, but during the production process, welding iron flange blank rarely detected, so after it, produced it, not after Detection of iron welding flange material is not guaranteed.

Welding Technology

Required equipment

Manual welding equipment set, handle an angle grinder, electric hammer one, a flat foot.

Welding preparation

1. Check debugging equipment to ensure normal operation of equipment; 2. Prepare φ4.0J402 electrodes best drying at 300 ℃ -350 ℃ for one hour.

Welding process

1, the assembly of the vertebral body and large flanges are assembled together by drawing, and then average the Dharma Blue divided into 8 equal parts. 2, due to the large flange welding thick groove, and therefore the use of sub-symmetric multilayer welding.

Weld quality

Weld strength requirements at least reach the base metal strength. Weld smooth surface, no burn, porosity, weld leak, slag, undercut, incomplete full and other defects. I height of less than 2mm.


1, must use the J506 electrode manual welding when backing, and a small current welding. In strict accordance with the welding process of welding. 2. After each completed welding position, should use the card at the level of foot deformation of the flange plane. 3, while the welding seam side with a hammer hammer, in order to achieve the role of stress relief.

Flange gasket

Rubber flange gasket

Rubber flange gasket

A gasket is capable of plastic deformation, and having a ring made of a material a certain intensity. Most of the gasket is cut down from the metal sheet, or by a professional production factory according to predetermined size, the material is asbestos rubber sheet, asbestos sheet, PTFE sheet, polyethylene sheet and the like; it also uses a thin metal plate (white metal, stainless steel) will wrap up the non-metallic materials such as asbestos gasket made of metal package; there is a winding made together with the spiral wound gasket with a thin strip of asbestos, the most commonly used is stainless steel and graphite entwined The metal spiral wound gasket, depending on the environment, it can be wrapped with asbestos. Ordinary rubber gasket suitable temperature below the case 120 ℃; asbestos rubber gasket suitable for steam temperature below 450 ℃, the temperature of the oil is below 350 ℃, pressure of less than 5MPa occasions, for general corrosion medium, most commonly used is acid-proof asbestos board. In the high-pressure equipment and piping, copper, aluminum, steel No. 10, the lens type or other shapes metal gasket made of stainless steel. Contact width high pressure washer and the sealing surface is very narrow (line contact), the gasket sealing surface and high finish machining.

Low pressure small diameter wire flange, high pressure and low pressure are the use of large-diameter welded flange thickness and bolt diameter and the number of different connection flange pressures are different.

Related species

Reducing flange

Product Name: Reducing flange

Technical parameters: in accordance with national standards

Quality standards: in strict accordance with the relevant standards formulated by the state manufacturing

Product Specifications: DN15-DN2000

Packaging: wooden or other

Color: metal color

Features: anti-corrosion, acid and alkali, long life, reasonable prices, smooth, acid and alkali, high temperature, appearance, texture and strong performance

Production process: professional overall forging, forging manufacturing, plate cutting system, plate rolling, etc.

Processing methods: high-precision CNC lathe turning, fine turning lathe, welding and other processing

Nominal sch5s, sch10s, sch20s, sch30s, sch40s etc.

Manufacturing standards: GB, American standard, the Russian standard, Japanese standard, etc.

Material: 201,304.316.316L.0Cr18Ni9.321.202 etc.

Uses: Widely used in water conservancy, electricity, power plants, pipe fittings, industry, pressure vessels, etc.

Connection: flange nut, bolt connection.

Stainless steel flanges

Stainless steel flanges

Stainless steel flanges

Name: Stainless Steel Flanges English (Stainless steel flange)

Size: 1/2 “to 240” (10-6000)

Pressure rating: 0.6Mpa ~ 32Mpa, 150Lb ~ 2500Lb, PN0.25-PN42.0

Material: 304,304L, 321,316,316L, 310S and other materials

Ministry of Chemical Industry Standard: HG5010-52 ~ HG5028-58, HGJ44-91 ~ HGJ65-91, HG20592-2009 (PN series), HG20615-2009 (Calss series)

Applications: boiler and pressure vessel, petroleum, chemical, shipbuilding, pharmaceutical, metallurgy, machinery, food and other industries.

Pressure vessel flange

Product Name: Pressure vessel flange

Specifications: DN300 ~ 3000

Memo: pressure vessel flange Industry: HVAC Power building water supply pressure vessel fittings, pressure pipe fittings.

Category: Flange

Industry: HVAC Power building water supply pressure vessel fittings, pressure pipe fittings.

Applications Technical Data

Seal nominal pressure PN, MPa (bar) 0.6 1.0 1.6 2.5 4.0 6.4

Convex surface (MFM) DN1300 ~ 3000 DN300 ~ 3000 DN400 ~ 2000 DN300 ~ 800

Tongue and groove (TG) DN1300 ~ 3000 DN300 ~ 3000 DN300 ~ 3000 DN300 ~ 800

The whole plane (FF) DN300 ~ 3000 DN300 ~ 3000 DN300 ~ 3000 DN300 ~ 800

Flat welding flange

Flat welding flange includes plate flat welding flange, with neck flat welding flange.

Plate flat welding flange (PL)

Plate flat welding flange structure diagram

Plate flat welding flange structure diagram

Flat welding flange for nominal pressure of not more than 2.5MPa pipe connection. Flat welding flange sealing surface can be made smooth style, bump style and tenon slot three. Smooth application of the maximum flat welding flange. used for medium conditions are relatively mild cases, such as low pressure non purify compressed air, low pressure circulating water.

With neck flat welding flange sketch

With neck flat welding flange sketch

With neck flat welding flange (SO)

With neck flat welding flange height of the lower neck, stiffness of the flange, the carrying capacity increased. Compared with welded flange, welding workload, electrode consumption is high, it can not withstand high temperature and pressure, and repeated bending and temperature fluctuations, but on-site installation more convenient, you can omit the step of weld rubbed film hurt more popular.

Weld neck (WN)

Welded Flanges: Welding neck flange is generally referred to as “high-hub” flange. Its purpose is to divert pressure pipes, thereby reducing the high stress concentration at Frankie. Welding neck flange welded who is the best design since the value of its inherent structural provide flange. But the price is relatively high, because the complexity of the production process of products.

Thread (thread) Flange: The threaded flange is threaded to connect. But the center of the tube products have corresponding thread size. Its main advantage is that it can not weld assembly.

Sliding flange: sliding flange has a lower hub because the pipe into the top single flange welding. It is welded inside and outside to provide sufficient strength to prevent leakage. Sliding flange, matching all bored slightly larger outer diameter of the pipe. They are better than the neck flange welding, due to lower initial cost, a lot of users, but probably not the last installation costs low, less because of the increase in weld neck flanges.

Lap Flanges: in fact, exactly the same lap flange sliding flange, unless it is a radius between the hole and the flange race. This is necessary to accommodate the overlapping radius flange stub end. Typically, at the end of lap lap stub mating flanges and will be equipped with the system together.

The socket welding flange is similar to a sliding flange, unless it has a hole and anti-hole size. Match counter bore pipe, so that the pipe is inserted into the flange similar sliding flange. In the smaller hole diameter is the same as the ID matches the same pipe. Restriction hole is built as a shoulder sleeve designed for pipeline stays at the bottom. This eliminates any traffic restrictions in the use of socket welding flanges.

Socket weld flange (SW)

Socket welding flange

Socket Welding Flange

Socket welding flange

Socket welding flange

Sealing surface in the form of: projecting face (RF), uneven surface (MFM), tongue and groove (TG), ring joint face (RJ)

Material: Carbon Steel (Carbon Steel): ASTM A105,20 #, Q235,16Mn, ASTM A350 LF1, LF2 CL1 / CL2, LF3 CL1 / CL2, ASTM A694 F42, F46, F48, F50, F52, F56, F60, F65 , F70;

Alloy Steel (Alloy Steel): ASTM A182 F1, F5a, F9, F11, F12, F22, F91, A182F12, A182F11,16MnR, Cr5Mo, 12Cr1MoV, 15CrMo, 12Cr2Mo1, A335P22, St45.8 / Ⅲ, 35CrMoV, 45CrMo, etc.

Manufacturing standards: ANSI B16.5, GB / T9117.1-2000-GB / T9117.4-200 etc.

Threaded flange (TH)

Threaded flange nominal diameter: DN8 ~ DN100 Working Pressure: 1.0 ~ 2.5 (MPa) plate threaded flange material: stainless steel, carbon steel, alloy steel.

Threaded flange Uses: For fire, gas, hot and cold water, air conditioning, air pipe, tubing, gauges, hydraulic pipes and other industrial and civil pipe thread locking and sealing.

Flange cover (BL)

Flange cover, also known as blind flanges, intermediate flange without holes for pipes sealed with a plug. The type of sealing surface in the form of more, with a flat, convex, concave and convex surfaces, tongue and groove, ring joint face.

Sealing surface: plane (FF), raised face (RF), uneven surface (MFM), tongue and groove (TG), ring joint face (RJ)

Production materials:

Carbon Steel (Carbon Steel): ASTM A105,20 #, Q235,16Mn, ASTM A350 LF1, LF2 CL1 / CL2, LF3 CL1 / CL2, ASTM A694 F42, F46, F48, F50, F52, F56, F60, F65, F70 ;

Stainless steel (Stainess Steel): ASTM A182 F304,304L, F316,316L, 1Cr18Ni9Ti, 0Cr18Ni9Ti, 321,18-8;

Alloy Steel (Alloy Steel): ASTM A182 F1, F5a, F9, F11, F12, F22, F91, A182F12, A182F11,16MnR, Cr5Mo, 12Cr1MoV, 15CrMo, 12Cr2Mo1, A335P22, St45.8 / Ⅲ.

Loose flanges

Weld neck loose flange ring

Loose flange welded Loose ring flange with a neck Loose plate flange welded ring Loose ring plate flat welding flange plate over the loose flange In addition, to meet the needs of post-locking device, the rod section has holes, these holes can be affected by vibrations when the bolt is not to loose. Some of the flange bolts not threaded rod to be meticulous, called the shank flange bolts. This is conducive to the coupling flange bolts by varying the force of steel There are special high strength bolts on the structure. head will become bigger and more dimensions have changed galvanized round is molten metal reacting with the iron matrix alloy layer.

Flat welding ring loose flange (PJ / SE)

Flat welding flange Loose ring flange can be active sheet, generally supporting the water supply and drainage fittings (on expansion joints most common), expansion joints at both ends have a flange on the factory when the factory directly and Engineering piping, equipment bolted. The purpose of using flat welding Loose ring flange is generally in order to save material, its structure is divided into two sections, tubes and pipes connected to one end portion, a head made of flanging, the flange portion on the sleeve cuffs. Flanges low grade material and partially used tubes and pipes of the same material, to achieve the purpose of saving material.

Flat welding ring loose flanges:

1, cost savings. When the pipe material particular, when the price is expensive, flange welding the same material cost is high.

2, is not easy or not easy to weld large processing or strength needed. Such as plastic pipe, glass pipe and the like.

3, ease of construction. When the connector flange bolt holes is not easy to find the corresponding positive or prevent future replacement of equipment flange bolt holes have changed and so on.

Flat welding ring loose flange drawbacks:

1, under pressure low.

2, welding rings at low intensity (especially when the thickness of 3mm or less)

Flat welding ring loose flange production standards:

GB: GB / T9112-2000 (GB9113 · 1-2000 ~ GB9123 4-2000?)

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: HG5010-52 ~ HG5028-58, HGJ44-91 ~ HGJ65-91

Flange Standard: HG20592-2009 (PN series) \ HG20615-2009 (Calss series)

Machinery of the standard: JB81-59 ~ JB86-59, JB / T74-1994, JB / T79-94 ~ JB / T86-94

Pressure Vessel: JB4700-2000 ~ JB4707-2000, JB1157-82 ~ JB1160-82 B16.47A / B B16.39 B16.48

Ring groove flange and flange cover

Large-diameter flange plates

Large-diameter high-neck flange

Blind character

6 loose flange welded ring

Rotating flange

Anchoring flange

Surfacing / cover welding flange

Marine lap welding steel flanges Standard: This standard applies to ship products, marine engineering products. The main materials are: carbon steel, alloy steel, low temperature steel, stainless steel.

Forged flange connection is the two pipes, fittings or equipment, and forged flange connection is an important connection pipeline construction. Forged flange connections easy to use, able to withstand greater pressure. In the industrial pipeline, the use of forged flange connection is very extensive. Within the family, the pipe diameter is small, and is a low pressure, invisible flange stamping elbow connection. If in a boiler room or a production site, full of flanged pipe and equipment. Chromium content of 0.1% to 0.5% (forged flange generally free of chromium), carbon content of 1.0% or less and forging manufacturing forged flange high temperature, some forged flange surface hardness (HRC) although You can reach ≥56 above (quenching layer is only about 15 mm), forged flange material because of its poor hardenability hardness of heart to only 30 degrees, under normal circumstances, often using forged flange water quenching process.

Flange cover (flange protection connector)

Flange protective cover is mainly used in all industrial corrosion flange connection.

Flange guard

Flange guard

It protects the product flange head for protecting flange surface (convex or circular connector). Double end studs and gaskets from corrosion. The product is suitable for 316 ss stainless steel and non-metallic (plastic), its manufacturing size from & frac12; “to 144” ANSI, API, and AWWA flange diameter. Flanges and flange head system filler combination can protect applications in harsh environments.

Flange sealing cap structure:

316 stainless steel or non-metallic belt

316 ss cast

316 ss jig worm

Closed groove neoprene layer (temperature -. 34.4 ° C to 82 ° C)

ECH rubber pad (temperature -. 34.4 ° C to 149 ° C) 5 psi safety relief valve can be released

Fame Rise Flanges enclosures advantages:

Easy to install

No special tools

Easy to detect

Connection durable (easily damaged)

UV stable non-metallic materials


Flange packing system

A suitable temperature to 80 ° C.

Flange packing is a long-term plan to solve corrosion problems unique.

Flange filler is a polar polymer-based composite coating. It forms a paste can be used without pretreatment. Viscoelastic material into the recipe to make this pitch and voids, can produce an excellent anti-corrosion seal.

Flange packing Flange packing system for its ease of use and save time and money. Provide long-term protection.

Performance: excellent adhesion to steel, FBE (fusion epoxy powder), polyurethane, polyvinyl advanced weathering resistance / salt temperature range from -51 ° C to 80 ° C to fill the entire gap removable / reusable flange surfaces without excessive use of flexible pre-nozzle injection gentle manual or pneumatic gun. This ensures that the sealing tape before wrapping with CZ annular gap is completely filled.

E-2400 / E2000 high temperature flange fillers – suitable for 149 ° C temperature.

E-2400 / E2000 high temperature corrosion protection flange connection flange filler at temperatures up to 149 ° C high temperature from corrosion and design products.

E-2400 / E2000 is a non-electrolytically with a gel for steel flanges, bolts, pipes and structures corrosion protection.

With the ASTM-B1117 salt spray test nut bolt assembly performed 2,000 hours of testing, with the E2000 / 2400 protected area can still be turned by hand. Proper use of E2000 / 2400 to help protect the flange connection from corrosion.

High temperature flange seal

Flange components often require high temperature high temperature sealing plane, if there is no good sealant additional pressure seal in a separate area, by the pressure on, it will cause production inaccuracies or deformation, that is to say in a separate pressure zone in the pressure By leakage, thereby requiring unscheduled repair. In the field of application of high-temperature flat seal preferably is Boke Si high-temperature sealant, its special formula to keep inert gas turbines and steam and standard applications in high temperature flange, it can withstand the hot air, steam, water, light fuel oils and lubricants, can be resistant to crude oil and natural gas. It is a one-component, paste sealants, industrial applications, high-quality sealing compound, suitable for smooth, flat sealing surfaces (butt joints) requires high temperature and pressure conditions. Use a knife or rubber spatula spread plaster painted in a dry surface. Since sealing products will not cure, but it will slightly change the consistency, maintain flexibility and elasticity, and therefore there is no time requirement to use, the construction is completed can be put into operation immediately, without waiting. To repair the damage of high temperature sealing surface scratches, should cooperate Bo Kesi temperature F Series repair products.

Production Standard

GB: GB / T9112-2010 (GB9113 · 1-2010 ~ GB9123 · 4-2010)

Ministry of Chemical Industry Standard: HG5010-52 ~ HG5028-58, HGJ44-91 ~ HGJ65-91, HG20592-2009 series, HG20615-2009 series

Machinery of the standard: JB81-59 ~ JB86-59, JB / T79-94 ~ JB / T86-94, JB / T74-1994

Pressure Vessel: JB1157-82 ~ JB1160-82, JB4700-2000 ~ JB4707-2000 B16.47A / B B16.39 B16.

Standard System

Standard pipe flanges on two main international system, namely the German DIN (including the former Soviet Union), represented by the European pipe flange system and the US ANSI pipe flanges as a representative of the Inter-American pipe flange system. In addition, there are Japanese JIS pipe flanges, but in the petrochemical unit generally used only for public works, and less influence in the world. Now countries flange Introduction in the following:

1, with Germany and the former Soviet Union as the representative of the European System of pipe flanges 2, Inter-American system of standard pipe flanges to ANSI B16.5 and ANSI B 16.47 represented 3, Britain and France standard pipe flanges, the two countries have two casing flanges.

In summary, the internationally accepted standard pipe flanges can be summed up in two different and not interchangeable flange system: a representative of Germany’s European pipe flange system; the other is the US Representative American pipe flange system.

IOS7005-1 is a standard promulgated by the International Standards Organization in 1992, the standard is actually the United States and Germany, two series of pipe flanges merger of standard pipe flanges.

Production Process

The production process is divided into forging, casting, cutting system, rolling four.

Casting and forging flange flange

Cast out of the flange, blank shape and size is accurate, small processing volume, low cost, but there are casting defects (pores cracks inclusions.); Castings streamline the internal organization of the poor (if it is cutting elements, streamlined worse);

Forging flange flange is generally lower than the carbon rust casting, forging streamlined good, the organization is relatively compact, mechanical properties superior to casting flange;

Improper forging process also occurs large grains or uneven hardening crack phenomenon, forging costs than cast flange.

Forgings than casting can withstand higher shear and tensile forces.

Casting advantage is that it can produce more complex shape, the cost is relatively low;

Forging advantage is that even within the organization, there is no casting porosity, inclusions and other harmful defects;

From the difference between the production process of casting and forging flange flange different, such as belonging to a centrifugal casting flange flange.

Centrifugal casting method of producing a precision flange flange, the more common kind of casting sand casting organization much fine, quality improved greatly, loose tissue, pores, trachoma and other issues is not easy to appear.

First, we need to understand how to produce centrifugal flanges are made, centrifugal casting making welded flange process method and product, characterized in that the product has been processed by the following process steps:

① selected raw steel into the melting furnace, the molten steel temperature reaches 1600-1700 ℃;

② metal mold preheated to 800-900 ℃ constant temperature;

③ start the centrifuge, the step ① Step ② the molten steel into the preheated mold;

④ holding the casting was allowed to cool to 800-900 ℃ 1-10 minutes;

⑤ water cooled to near room temperature, remove the casting mold release.

We come to understand the production process of forging flange:

Forging process generally consists of the following steps, namely select lower quality billet materials, heating, forming, cooling after forging. The process of forging free forging methods, forging and mold forging. Production, according to the size of the forging quality, how many choose a different method of forging production lot.

Free forging low productivity, large allowance, but the tool is simple, versatile big, it is widely used in forging the shape of a relatively simple one-piece, small batch production of forgings. Free air hammer forging equipment, steam – air hammer and hydraulic machines, respectively, for small, medium and large forgings production. Forging high productivity, simple operation, easy to implement mechanization and automation. Forging high dimensional accuracy, small machining allowances, forging a more reasonable distribution of fibrous tissue, can further improve the service life of the part.

Fundamental freedoms forging process: the free forging, forging shape is deformed by some basic steps will gradually forged into billets. The basic steps are free forging upsetting, stretching, punching, bending and cutting and so on.

1. upsetting upsetting is the axial direction of the original blank forging to highly reduce operating process cross section increases. This process commonly used in forging gear blanks and other disc-shaped forgings. All upsetting upsetting divided into partial upsetting two.

2. Stretching Stretching is to increase the length of the blank forging steps to reduce the cross-section, usually used to produce rough shaft parts, such as the lathe spindle, connecting rods.

3. perforating punch in the blank out of the through holes or blind hole of the forging process.

4. bending the blank bent or angled shape forging process.

5. reversing a portion of the blank relative to the other portion of the rotating angled forging process.

6. The cutting or removal of the blank forging steps split feed head.


The full name of the model forging forging, the blank is placed in a heated die forging fixed in the forging of the device.

The basic step of forging the forging process: cutting, heating, pre-forging, the final forging, punching skin, cutting, quenching, shot peening. Common processes are upsetting, stretching, bending, punching, molding.

Common forging equipment commonly used equipment forging hammer forging, hot forging presses, horizontal forging machines and friction presses and the like.

More simply, better quality forged flanges, typically by forging production, fine crystal structure, high strength, and of course the price is expensive.

Whether it is casting flange or flange forged flanges are all commonly used in the manufacturing method, see the strength requirements required to use part of, if not ask, you can also use the system for turning flange.

Third, the cutting system flange

Board cut in direct processing capacity left within the outer diameter and thickness of the disk flange, and then machining the bolt holes and waterline. This produced a flange cutting system called flanges, such flanges with a maximum diameter of the plate width is limited.

Fourth, the rolling flange

Cut strips with a plate and then rolled into a circle called the rolling process, used for the production of some large flange. After the successful roll welding, then flattened, then the waterline and bolt hole machining process.


In the continuous production of modern industrial flange by corrosion, erosion, temperature, pressure, vibration and other factors, it will inevitably arise leaks. Sealing surface machining size due to aging error, the sealing element and improper installation of the fastening flanges and other reasons can easily cause leakage. If not timely treatment flange leakage, leakage will rapidly expand in the medium erosion, loss of materials, destruction of production environments, leading companies down to stop production, causing huge economic losses. If a major accident is poisonous, flammable and explosive media leaks, it may also cause poisoning, fire or explosion.

Traditional solutions flange leakage method for the replacement of the sealing element and replace Apply sealant or flange and pipe, but the method has great limitations, and some leakage workplace safety requirements that limit can not be resolved on-site . Now you can use a polymer composites scene plugging, which apply more mature Blessed blue world system. It is an ideal method, especially in explosive situations, but also demonstrate its unique advantages. Polymer composite materials technology construction technology is simple, safe, and low cost, it is possible for enterprises to solve most of flange leakage problems, eliminate security risks, enterprises save more maintenance costs. [1]


GB flange English (National standard flange) refers to the People’s Republic of China national standards “GB / T 9112 ~ 9124-2010 steel pipe flanges” provisions flange piece production.

GB flange standard by the General Administration of Quality Supervision, Inspection and Quarantine of People’s Republic of China and the Standardization Administration of China jointly issued on 2011-01-10, recommended standards implemented since the 2011-10-01.

GB / T 9112 ~ 9124-2010 total includes the following 13 criteria:

Instead of GB GB / T9112-2000; GB / T10745-1989 standard

GB / T 9112-2010 Types and parameters for steel pipe flanges

GB / T 9113-2010 Integral steel pipe flanges

GB / T 9114-2010 with neck steel pipe flange

GB / T 9115-2010 welded steel pipe flange

GB / T 9116-2010 with neck flat welding steel pipe flanges

GB / T 9117-2010 with neck socket welding steel pipe flanges

GB / T 9118-2010 welded ring Loose hubbed steel pipe flanges

GB / T 9119-2010 plate flat welding steel pipe flanges

GB / T 9120-2010 butt Loose plate steel pipe flanges

GB / T 9121-2010 Loose plate flat welding steel pipe flanges

GB / T 9122-2010 flange Loose plate steel pipe flanges

GB / T 9123-2010 Steel pipe blank flanges

GB / T 9124-2010 steel pipe flanges

Technical conditions

This standard specifies pressure PN markers and markers into Class tags.

PN labeled with 12 pressure levels

Respectively: PN2.5; PN6; PN10; PN16; PN25; PN40; PN63; PN100; PN160; PN250; PN320; PN400

Class labeled with 6 pressure levels

They are: Class 150; Class 300; Class 600; Class 900; Class 1500; Class 2500

GB flange of another layer of meaning: In accordance with the requirements of national standard dimensions, tolerances and other production of flange, different from the standard sizes not produced, also known as two standard flange piece flange (someone called non-standard flange is incorrect), usually some unscrupulous businesses will reduce flange thickness, the outer diameter of the two dimensions to achieve the purpose of saving material, as well as with scrap steel or scrap steel processing flange, generally this steel chemical composition and mechanical performance is not up to the waste, and some even use black steel flange private steel production, steel making technology this private use of obsolete steelmaking can not guarantee the mechanical properties and weldability, there may not be time to use and pipe welding, or Steel itself has cracks, holes and other leaks will go up after welding, so try to use national standard flange flange time of purchase. If we must look closely at funding a limited selection of two standard flange case and flange dimensions so as not to be fooled measure.

Professional processing equipment

Manufacturing large-diameter flange have a professional equipment in order to achieve more effective, professional equipment CNC milling disc, the bulk of lathes and other


Since the flange has a good overall performance, so it is widely used in chemical, construction, water supply, drainage, oil, light and heavy industrial, refrigeration, sanitation, plumbing, fire protection, electric power, aerospace, shipbuilding and other infrastructure projects.