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Flange connection (flange, joint) consists of a pair of flanges, a gasket and several bolts and nuts. The gasket is placed between the sealing surfaces of the two flanges. After the nut is tightened, the specific pressure on the surface of the gasket will deform when it reaches a certain value, and fill the unevenness on the sealing surface to make the connection tight and leak-proof. Flange connection is a detachable connection. According to the connected parts, it can be divided into container flange and pipe method; according to the structure type, there are integral flange, looper flange and threaded flange. Common integral flanges include flat welding flanges and butt welding flanges. Flat welding flanges have poor rigidity and are suitable for occasions where the pressure is p≤4MPa; butt welding flanges, also known as high neck flanges, have higher rigidity and are suitable for occasions with high pressure and temperature. There are three types of flange sealing surfaces: flat sealing surface, suitable for occasions where the pressure is not high and the medium is non-toxic; concave and convex sealing surface, suitable for occasions with slightly higher pressure; Tongue and groove sealing surface, suitable for flammable, explosive, toxic media and high pressure occasions. Butt welding flange gasket is a ring made of material that can produce plastic deformation and has a certain strength. Most of the gaskets are cut from non-metallic sheets, or made by professional factories according to the specified size, and their materials are asbestos rubber sheets, asbestos sheets, polyethylene sheets, etc.; There are also metal clad gaskets made of thin metal plates (white iron, stainless steel) wrapped around non-metallic materials such as asbestos; there is also a wound gasket made of thin steel strips and asbestos strips. Ordinary rubber gaskets are suitable for occasions where the temperature is lower than 120 °C; asbestos rubber gaskets are suitable for occasions where the temperature of water vapor is lower than 450 °C, the temperature of oil is lower than 350 °C, and the pressure is lower than 5MPa. The most commonly used medium is acid-resistant asbestos board. In high-pressure equipment and pipelines, lens-type or other-shaped metal gaskets made of copper, aluminum, 10-gauge 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 the gasket is high. The low-pressure small diameter has a wire flange, and the high-pressure and low-pressure large diameter use welded flanges. The thickness of the flanges and the diameter and number of connecting bolts are different for different pressures.

1. At present, there are 4 flange standards in my country, which are: (1) National flange standard GB/T9112~9124-2000; (2) Chemical industry flange standard HG20592~20635-1997 (3) Mechanical Industry flange standard JB/T74~86.2-1994; (see: Flange standard of the Ministry of Machinery) (4) The petrochemical industry flange standard SH3406-1996. Now take the national standard as an example to illustrate the choice of flange. The national standard flange is divided into two systems: the European system and the American system. The nominal pressure of European system flanges are: PN0.25, PN0.6, PN1.0, PN1.6, PN2.5, PN4.0, PN6.3, PN10.0 and PN16.0MPa; American system flanges Nominal pressures are: PN2.0, PN5.0, PN11.0, PN15.0, PN26.0 and PN42.0MPa 2. The basis for selecting flanges (1) The nature of the conveying medium, general medium, special medium, toxic Medium, flammable and explosive medium; (2) According to the parameters of the medium, working pressure, working temperature, in the case that the medium is determined, determine the nominal pressure PN of the flange according to the working temperature and working pressure of the medium. (3) Determine the connection method and sealing surface form of flange and pipe according to the place of use and connection conditions. (4) Determine the flange specification according to the connection object.

Loose flange blank Commonly used as a connection is a change in material. Loose flange is the use of flanges, steel rings, etc. to cover the flange on the pipe end, and the flange can move on the pipe end. The steel ring or flange is the sealing surface, and the function of the flange is to compress them tightly. From this, it can be seen that due to being blocked by steel rings or flanges, the loose flange does not come into contact with the medium. Loose flange is suitable for connecting non ferrous metals such as steel and aluminum, as well as stainless and acid resistant steel containers, and for corrosion resistant pipelines. Loose flange is a movable flange that is usually attached to water supply and drainage accessories (most commonly on expansion joints). When the manufacturer leaves the factory, there is a flange at both ends of the expansion joint, which is directly connected to pipelines and equipment in the project with bolts. It's the type of flange with a looper. Usually used on pipelines, in that case, loosening the bolts can rotate the pipes on both sides and then tighten them. It allows for convenient disassembly and assembly of pipelines. Loose flange is also known as loose flange.

The pressure markings specified in this standard are divided into PN markings and Class markings. PN marking has 12 pressure levels Respectively: PN2.5; PN6; PN10; PN16; PN25; PN40; PN63; PN100; PN160; PN250; PN320; PN400 The Class tag has 6 pressure levels Respectively: Class 150; Class 300; Class 600; Class 900; Class 1500; Class 2500 Another meaning of carbon steel flanges is: flange plates produced according to the dimensions, tolerance range, and other requirements of national standards. Different from flange plates not produced according to standard dimensions, which are also known as non-standard flanges (some people call non-standard flanges incorrect), some unscrupulous merchants usually reduce the thickness and outer diameter of the flange plate to achieve the purpose of saving materials, and also use waste steel or scrap steel to process flanges, Usually, this type of steel is a waste material with substandard chemical composition and mechanical properties. Some even use black steel plants to produce flanges through private steelmaking. The steelmaking technology used in this type of private steelmaking is outdated and cannot guarantee mechanical and welding properties. When used, it may not be able to weld with the steel pipe, or the steel itself may leak water after welding with cracks, pores, etc. So when purchasing flanges, try to choose carbon steel flanges as much as possible.

1. Different connection methods The biggest difference between the necked flat welding flange and the necked butt welding flange is the connection method of the pipe and the flange. Flat welding flanges with necks are usually connected at flange angles, while butt welding flanges with necks are butt joints between flanges and pipes. The flat welding flange with neck can only be connected to the pipeline, and cannot be directly connected to the butt welded pipeline. Neck butt weld flanges can generally be directly attached to all butt weld fittings, including pipes. The stiffness of the butt welding flange with neck is higher than that of the flat welding flange with neck, and the strength of butt welding is higher than that of the flat welding flange, and it is not easy to leak. The necked flat welding flange and the necked butt welding flange cannot be replaced at will. From a manufacturing point of view, flat welding flanges with necks have large internal warpage, light weight and low cost. In addition, butt welding flanges with necks with a nominal diameter greater than 250mm are also tested, and the flanges do not need to be tested, so the cost is relatively low. Flat welding flanges with necks are widely used in imported petroleum equipment, similar to American standard S0. Weld neck flanges are used for hazardous media. Neck butt welding flange refers to the pipe diameter and wall thickness of the connecting end. Same as the pipe to be welded, just like welding two pipes. Flat welding and butt welding refer to welding methods for flange and pipe connections. When welding flat welding flanges, only one side welding is required, and there is no need to weld pipes and flange connections. The welding installation of welded flanges requires double-sided welding of the flanges. Therefore, flat welding flanges are usually used for low pressure and medium pressure pipelines, and welded flanges are used for medium and high pressure pipeline connections. The welded flanges are usually at least PN2.5MPa, and butt welding is used to reduce stress concentration. Therefore, due to the increase of the process, the installation cost, labor cost and auxiliary material cost of the welded flange are higher. 2. Different welding forms Flat welds cannot be radiographically inspected, but butt welds can. The butt weld at the neck is the girth weld between the flange and the pipe. Flat welds are two fillet welds and butt welds are butt girth welds. The difference between a flat welding flange with a neck and a flat welding flange without a neck is that a flat welding flange with a neck has more welds in the pipeline than a flat welding flange without a neck. A flat welding flange without a neck is also a flat welding flange, and a flangeless boss is also a right angle welding. The weld between the neck butt flange and the connecting pipe belongs to the B-type weld, while the weld between the neck flat welding flange and the connecting pipe belongs to the C-type weld, and the non-destructive testing after welding is different. 3. Different materials The necked flat welding flange material is processed with thick ordinary steel plate according to the requirements, and the necked butt welding flange material is mainly processed with forged steel parts. different nominal pressures The nominal pressure of the necked flat welding flange is 0.6-4.0MPa, and the nominal pressure of the necked welding flange is 1-25MPa; the welding seam between the necked butt welding flange and the pipeline belongs to the B type weld, while the flat neck method The weld between the flange and the pipe joint belongs to the class C weld, and the non-destructive testing after welding is different. Flat welding flanges with necks and welding flanges with butt joints cannot be replaced at will. From the manufacturing point of view, the shrinkage flange has large internal warpage, light weight and low cost. In addition, if the nominal diameter is greater than 250mm, the welding flange should also be tested, and the flange does not need to be tested, and the cost is low.

It is made of dual-phase steel, mainly containing carbon, manganese, nickel, silicon, chromium, copper, molybdenum, nitrogen and other elements. In addition, the density of s32750 is 8.03g per cubic centimeter, the melting point is between 1300 and 1390 degrees, and its moisturizing effect between 1000 and 1052 degrees is 1 to 2 hours, which can be quickly air-cooled. How to maintain copper products 1. The copper products have been used for a long time, and there will be grease and dust on the surface. At this time, you can use distilled water to clean, heat the distilled water, and then add detergent to mix. Then you can use a rag to dip and wipe the copper products, which can effectively remove the dirt. After cleaning, rinse with distilled water for several times. 2. If the volume of copper products is relatively large and very heavy, the dust collector can be used for dust removal, which is very convenient and can effectively remove substances. If there is hollow-out design for copper products, high-pressure air pump can be used to improve the cleaning effect. 3. If bronze products are placed in the home, it is necessary to regularly observe whether there are problems. If bronze diseases are found, it is necessary to use special reagents for cleaning in time. In case of serious rust and corrosion, it is necessary to contact professional personnel for cleaning. 4. During the maintenance of copper ware, many people will choose to apply a layer of paraffin on its surface, which is very good, but it is easy to cause dust on the surface of copper ware, which is not conducive to beauty. However, applying silicone can better avoid this problem and prevent harmful gases.

Flanges are flanged parts. Flanges can be separate, called flanges, or combined, such as flanges at both ends of the valve, for easy installation of bolts. This article will introduce the material of the flange, the sealing surface form of the flange, and the classification of flanges according to national standards and chemical, petrochemical, and mechanical standards. material 20# A105 Q235 A12Cr1MoV 16Mn R15CrMo18-8321 304 304L 316 316L Form of sealing surface Flat (FF) Raised (RF) Convex (M) Concave (F) Concave and convex surface (MF) Tenon surface (T) Groove surface (G) Tenon and groove surface (TG) Ring connection surface (RJ) According to national standards Integral Flange Threaded Flange Butt Welding Flange Neck Welding Flange With neck socket welding flange butt welding ring with neck loose flange plate flat welding flange butt welding ring plate loose flange Flat Welded Ring Plate Loose Flange Flanging Ring Plate Loose Flange Flange Cover According to chemical industry standards Integral Flange (IF) Threaded Flange (Th) Plate Flat Welding Flange (PL) Diameter Butt Welding Flange (WN) Flat Weld Neck Flange (SO) Socket Weld Flange (SW) Butt Weld Ring Loose Flange (PJ/SE) Flat Weld Ring Loose Flange (PJ/RJ) Lining Flange Cover (BL(S)) Flange Cover (BL) According to petrochemical industry standards Threaded Flange (PT) Butt Welding Flange (WN) Flat Welding Flange (SO) Socket Welding Flange (SW) Loose flange (LJ) flange cover (not shown) According to machinery industry standards Integral flange butt welding flange plate flat welding flange butt welding ring plate loose flange Flat Welded Ring Plate Loose Flange Flanging Ring Plate Loose Flange Flange Cover

Flange, also known as flange flange or flange. Flanges are the parts connecting pipes and pipes, which are used for the connection between pipe ends; The flange on the equipment inlet and outlet is also used for the connection between two equipment, such as the reducer flange. Flange connection or flange joint refers to the removable connection of flange, gasket and bolt as a group of combined sealing structure. The pipe flange refers to the flange used for piping in the pipeline device, and the inlet and outlet flanges of the equipment when used on the equipment. There are holes on the flange, and bolts make the two flanges tightly connected. The flanges are sealed with gaskets. The flange is divided into threaded connection (threaded connection) flange, welding flange and clamp flange. Flanges are used in pairs. Wired flanges can be used for low pressure pipes, and welded flanges can be used for pressure above 4kg. Add a gasket between the two flanges and fasten them with bolts. The thickness of flange under different pressure is different, and the bolts used are also different. When pumps and valves are connected with pipes, parts of these equipment are also made into corresponding flange shapes, also known as flange connection. All connecting parts that are bolted around two planes and closed at the same time are generally referred to as "flanges", such as the connection of ventilation pipes. Such parts can be referred to as "flange parts". But this kind of connection is only a part of the equipment, such as the connection between the flange and the water pump, so it is not easy to call the water pump "flange parts". Smaller parts such as valves can be called "flange parts". Reducer flange is used for the connection between motor and reducer, as well as the connection between reducer and other equipment.

In modern chemical and petrochemical industries, products in the form of annular billets of 'flange' type are widely applied for connecting the various pipe-lines. The flanges are operated under severe climate conditions and therefore, strict inspection of them is performed. The flanges are manufactured from steels of St20, 09G2S, 10G2, 08Kh18N10T grades. The steel are made in electric furnaces. However quality of cast steels is not high, and additional treatment such as forging is applied. It has been shown that high-quality castings can be produced by method of centrifugal electroslag casting. Flux contains calcium fluoride, corundum, magnesite, and silica in this case. High-quality flanges are produced.

1.4432 hydrogen is added on the basis of 316, but the carbon content is at its upper limit. It is mainly used for heat resistance applications where the thermal strength performance is higher than that of molybdenum free steel. It has good processing performance, welding performance and high-temperature oxidation resistance. X2CrNiMo17-12-3 - (1.4432) Grade (EU) X2CrNiMo17-12-3 Number 1.4432 USA 316L Japan, JIS SUS316L France, ANFOR Z3CND17-13-03 Z3CND18-14-03 England, BSc 316S13 Sweden, SS 2353 Russia, GOST 03KH17N14M3 main features It has good corrosion resistance in acidic and chloride containing environments, low sensitivity to stress corrosion cracking in the presence of chlorides, excellent resistance to intergranular corrosion (even after welding), excellent weldability, and is very suitable for use in environments with high risk of spot corrosion

The full name of die forging is die forging, which is formed by placing the heated blank in the forging die fixed on the die forging equipment. 1. Basic process of die forging: blanking, heating, pre forging, final forging, punching and peeling, trimming, tempering, shot peening. Common processes include upsetting, elongation, bending, punching and forming. 2. Common die forging equipment Common die forging equipment include die forging hammer, hot die forging press, flat forging machine, friction press, etc. Generally speaking, forged flanges are of better quality, generally produced by die forging, with fine crystal structure and high strength. Of course, the price is also higher. Both cast flange and forged flange belong to the common manufacturing method of flange. It depends on the strength requirements of the parts to be used. If the requirements are not high, turning flange can also be used.

Flange, also called flange plate or flange, is a part that connects pipes with each other. It is often connected to the top of the end and has a wide variety. 1. It can be divided into vessel flange and pipe flange according to the connected parts. 2. It is divided into integral flange, looper flange and threaded flange according to the structure type. Common integral flanges include flat welding flange and butt welding flange. 3. It is divided into threaded connection (screw connection) flange and welding flange according to the connection mode. Low pressure small diameter threaded flange, high pressure and low pressure Welding flanges are used for large diameters. 4. Plate type flat welding flange, neck flat welding flange, neck 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 and loose flange with butt welding ring.

The main production processes are mainly divided into forging, casting, cutting and coiling. The cast flange has accurate blank shape and size, small processing amount and low cost, but it has casting defects (pores, cracks, inclusions); The streamline of the internal structure of the casting is poor (even worse if it is a cutting part); Forged flanges have low carbon content, are generally less rusty than cast flanges, and have good streamline, dense structure, and superior mechanical properties to cast flanges; Improper forging process will also lead to large or uneven grains and hardening cracks, and the forging cost is higher than that of the casting flange. Forgings can withstand higher shear force and tensile force than castings. The advantage of the casting is that it can produce a more complex shape, and the cost is relatively low; The advantages of forgings are that the internal structure is uniform, and there are no harmful defects such as air holes and inclusions in the castings; Distinguish the difference between cast flange and forged flange from the production process flow. For example, centrifugal flange is a kind of cast flange. Centrifugal flange is produced by precision casting. Compared with ordinary sand casting, the structure of this kind of casting is much thinner, and the quality is improved a lot. It is not easy to have problems such as loose structure, porosity, and trachoma. First of all, we need to know how the centrifugal flange is produced. The process method and product of making the slip on flange by centrifugal casting are characterized by that the product is processed through the following process steps: ① Put the selected raw materials and steels into the medium frequency electric furnace for smelting to make the temperature of molten steel reach 1600-1700 ℃; ② Preheat the metal mold to 800-900 ℃ to maintain constant temperature; ③ Start the centrifuge, inject the molten steel in step ① into the metal mould preheated in step ②; ④ The castings shall be naturally cooled to 800-900 ℃ for 1-10 minutes; ⑤ Cool with water to near room temperature, demould and take out the casting.

High temperature flange components often need to be sealed with high temperature on the plane. If there is no good sealant for additional sealing in the separate pressure area, the production will be inaccurate or deformed under the influence of pressure, that is to say, leakage will occur in the separate pressure area under pressure, which requires unscheduled repair. At present, Bokos high-temperature sealant is better used in the field of high-temperature plane seals. Its special formula makes it inert in standard applications of steam and gas turbines and high-temperature flanges. Therefore, it can withstand hot air, steam, water, light fuel oil and lubricants, and can withstand crude oil and natural gas. It is a single component, paste sealant, industrial use, high-quality sealing mixture, and suitable for working conditions requiring high temperature and pressure for smooth and flat sealing surfaces (butt joints). Spread on the dry surface with a plaster knife or rubber scraper. As the sealing products will not cure, but their consistency will change slightly, and remain flexible and elastic, there is no time requirement in use, and they can be put into operation immediately after construction without waiting. If the high-temperature sealing surface with scratch damage needs to be repaired, it should be used in conjunction with Bokos high-temperature F series repair products.

Loose flange plate with flat welding ring is a movable flange, which is generally matched on the water supply and drainage fittings (the most common expansion joint). When the manufacturer leaves the factory, there is a flange at both ends of the expansion joint, which is directly connected with the pipeline and equipment in the project with bolts. The purpose of using loose flange plate with flat welding ring is generally to save materials. Its structure is divided into two parts: one end of the pipe is connected with the pipe, the other end is made into a flanging, and the flange plate part is sleeved on the flanging. The flange plate is made of low-grade materials, while the pipe part is made of the same materials as the pipe to save materials Advantages of slip on welding ring loose flange: 1. Cost savings. When the pipe material is special and expensive, the cost of welding flanges of the same material is high. 2. It is not convenient for welding or processing or requires high strength. Such as plastic pipe, glass steel pipe, etc. 3. It is convenient for construction. For example, it is not easy to align the flange bolt holes when connecting or prevent the flange bolt holes from changing when replacing equipment in the future. Disadvantages of slip on welding ring loose flange: 1. Low stress. 2. Low strength at the welding ring (especially when the thickness is less than 3mm)

welding technology Collapse required equipment A set of manual electric welding equipment, a handle type angle grinder, an electric hammer and a plane ruler. Preparation before folding welding 1: Check and commission equipment to ensure normal operation of equipment; 2. Preparation φ 4.0J402 welding rod should be dried at 300 ℃ - 350 ℃ for one hour. Folding welding process 1: Assemble the cone and large flange together according to the drawing requirements, and then divide the large flange into 8 equal parts. 2. Because the flange is thick and the groove is large, the welding is symmetrical in sections and multi-layer. Folding weld quality The weld strength is required to be at least that of the base metal. The weld surface shall be flat and smooth without burn through, air hole, weld leakage, slag inclusion, undercut, incomplete welding and other defects. The surplus height is less than 2mm. Notes on folding 1: During backing, J506 electrode must be used for manual surfacing and low current welding. Welding shall be carried out in strict accordance with the welding process. 2. After each welding position is completed, the deformation of the flange plane shall be checked with a level gauge. 3. While welding, hammer the weld with air hammer to eliminate stress.

What is the difference between butterfly valve flange and slip on flange? Today, Ningbo Xinggang Pipeline Equipment Co., Ltd., a wholesale manufacturer of butterfly valve flanges in Ningbo, will share with you the difference between butterfly valve flanges and flat welding flanges. The outer diameter thickness and center distance of the butterfly valve flange and the flat welding flange are the same. The difference between the butterfly valve flange and the flat welding flange is that the butterfly valve flange has one more inner groove, which is processed by one more process than the flat welding flange, so the price is higher than that of the ordinary flange. The butterfly valve flange is connected with the valve. There is a groove behind the butterfly valve flange, which is inserted into the steel pipe for welding, One or two or more margins are left on both sides of the groove (depending on the diameter of the butterfly valve flange). Flat welding flange is also called plate flat welding flange (PL). Flat welding flange is relatively cheap because of its simple structure and low material consumption. However, the rigidity and tightness are not as good as those of the neck butt welding flange. The flat welding flange is welded by inserting the pipe into the flange. Because of the poor rigidity, flat welding flange shall not be used in the chemical process piping system with flammable, explosive and high vacuum requirements, and in the highly hazardous occasions. Flat welding flange is widely used in connection of medium and low pressure vessels and pipelines. Flat welding flange is applicable to the connection of fluid pipelines with nominal pressure not exceeding PN2.5MPa. The sealing surface of flat welding flange can be made into three types: lubricating type, concave convex type and mortise groove type. The application of RF flat welding flange is the largest It is mainly used in the case of moderate medium conditions, such as low pressure vessel, water supply pipe network, non purified compressed air, low pressure circulating water, etc.

Carbon steel flanges have different hardness and strength in use and production, so it can probably play an important role and cost in use. Carbon steel flanges made of different materials can give play to different advantages and characteristics in use. Low carbon steel has good plasticity and low strength. It is probably necessary for flange connection to suffer from high tensile, compressive, torsional and shear strength. It should be used according to certain manufacturing examples and essentials for sealing pipe plugs. The carbon steel flange shall be produced according to the necessary different data and production configuration. The production data of the flange cover are as follows: the carbon steel flange is a flange without holes in the middle. It is guaranteed that good performance and advantages can be achieved, and production shall be carried out strictly according to the confirmed process and essentials. Carbon steel flange is a better choice. It will become firm after adding proper amount of carbon element. It may play a different role and cost in utilization. The shims required are also different. Flat face flange is usually only used for low pressure and carbon steel flange. The situation of flanges is different. Equipped with soft thin gasket; Under high pressure, if the strength of the flange is sufficient, the flat face flange can also be used, but thick soft gasket should be used, probably a wound gasket with inner reinforcing ring or reinforcing ring. In such places, metal gaskets are also not practical, because the required compression force is too large at this time, resulting in large deformation of the bolt, making it difficult to seal the flange. If metal gasket is used, the smooth surface shall be reduced to reduce the fighting area with the gasket. In this way, when the bolt tension is the same, the compression stress of the narrowed flat surface will increase.

1. Maintenance paint solution Repair paint is a hard coat that can be bonded directly to the substrate. There are many corners and edges on the flange. Because of the thin edge, the traditional coating system is difficult to cover the edge effectively. Although a thicker coating can solve the problem of edge protection, it will seal the fasteners and cannot be removed in future maintenance. 2. Mechanical solutions Flange and flange gap are mainly sealed by protective cover and clamp. It is usually made of stainless steel or plastic and is equipped with a rubber sealing strip. This method of protection is not very flexible. Housings or clamps that match flanges of all sizes must be stored. 3. Tape or semi-solid anticorrosive tape solution The roll packaging tape can be protected by wrapping it on the surface of the substrate. Because semi-solid polymers have better water resistance, this protection method can provide reliable corrosion protection. However, if the flange shape is complex, the material is not only time-consuming, but also difficult to construct. 4. Hot melt plastic solution Hot melt adhesive is essentially a wax like fusible polymer heated at high temperature and sprayed on the surface of the substrate by professional hot melt equipment. The advantage of this protection method is that it can be remelted and reused, thereby saving costs. Although this method can be reused, it also requires thermal work, professional equipment and building services. Although it can be reused, it is not easy to open and seal during maintenance. 5. Polymer sealing bag solution he sealing bag can completely cover the flange, and its composition is composed of low permeability polymer, corrosion inhibitor steam and desiccant, which is easy to install. However, the end of the bag is only sealed with tape, not a durable and effective mechanical combination. There is a large area of steam space in the bag, which tends to accumulate a large amount of water and consume corrosion inhibitors for a period of time.

Butt welding flange: neck flange welding is usually called "high hinge" flange. Its purpose is to transfer the pressure of the pipeline, thereby reducing the high stress concentration in Frankie. Neck flange welding is the best design for butt welding those currently available due to its inherent structural value. However, the price is relatively high, because the production process of the product is complex. Threaded (threaded) flange: the threaded flange is connected by screw thread. But the center of the product has a thread size corresponding to the pipe. Its main advantage is that it can be assembled without welding. Sliding flange: the sliding flange has a lower hinge because the pipeline enters the single flange before welding. This is welded internally and externally to provide sufficient strength to prevent leakage. The sliding flange is the matching of the slightly larger outer diameter pipe. They are superior to the welding of neck flange. Due to the low initial cost, many users, but the final installation cost is probably not the same, because there are fewer welding neck flanges added. Lap flange: the lap flange is actually identical to the sliding flange unless it has a radius between the hole and the flange race. It is necessary that the radius has a flange to accommodate the end of the lap stub. Usually, the lap flange and lap stub mate together at the end of the month to assemble the system. The socket welding flange is a similar sliding flange unless it has a hole and counter hole size. Counter holes slightly beer than O.D. pipes match so that pipes are inserted into flanges similar to sliding flanges. The diameter of the smaller hole is the same as the ID of the matching pipe. The restriction is a built-in hole that acts as a shoulder sleeve for the pipe to stay at the bottom. This eliminates any flow restriction in the use of Socket Weld flanges.