法兰结构密封面形式（Flange structure cover form）

法兰结构密封面形式（Flange structure cover form） 法兰结构密封面形式(Flange structure cover form) Flange structure: According to the structure of the flange and the connection of the pipe can be divided into: the integral flange, with threaded flange, butt welding neck flange, with flat welding neck flange, socket welding neck flange, loose flange (loose tube containing four different components) and the flange cover (also known as the blind flange). The integral flange is a flanges of the pump, valve, machine, etc., which is used to connect the flange to the pipe. These inlet and outlet flanges are usually integrated with mechanical equipment as part of the equipment. Flanges are usually moulded with equipment and few are forged, such as end flanges on steel valves. The threaded flange is used to process the inner hole of the flange into pipe thread, and it is connected with the threaded pipe, which is a non-welding flange. The thread flange has the characteristics of installation and maintenance compared with welding flange, which can be used in some of the pipelines that are not allowed to be welded. The alloy steel flange has sufficient strength, but not easy to weld, or the welding performance is not good, may also select the threaded flange. But in the pipe temperature changes or sharply temperature higher than 260 ? C Under the condition of less than 45 ? C -, it is suggested that do not use the threaded flange, to avoid leakage. Butt welding flange is also called the high neck flange, it differs from the flange with other flange and pipe welding place to have a long and sloping high neck flange plate, this section of the wall thickness along the height direction of the high neck gradually transition to the wall thickness, improved the discontinuity of stress, thus increasing the intensity of the flange. The butt welding flange is mainly used for the demanding situation. Such as thermal expansion or other pipe and make the stress of the flange of the larger or stress changes repeatedly, pressure, temperature fluctuations in a pipe or high temperature, high pressure and low temperature pipes below zero. Flanged flange is also called lap welding flange. Flat welding flange and pipe connection is to insert the pipe flange hole to the appropriate position, then take welding, its advantage is that when the welding assembly for more easily, and the price is cheap, thus has been widely used. According to the internal pressure calculation, the strength of the flanged flange is about two thirds of the corresponding welding flange, and the fatigue life is about one third of the welding flange. Therefore, the flanged flanges only apply to low pressure level, pressure fluctuation, vibration and concussion are not serious pipe systems. Flat welding flange can be divided into two kinds: neck and flat welding and plate. The shape of the socket welding flange is the same as that of the flanged flange. It has a socket on the inner hole of the flange, and the pipe is inserted into the socket, and the weld is welded on the back of the flange. Because of the gap between flanges and pipes, sometimes it is easy to corrode, and if it is welded together, it can avoid such corrosion. The fatigue strength of welding flange is 50 %, and the static strength is the same. When using this flanged, the inner diameter of the flange should be consistent with the inner diameter of the pipe. The socket welding flange is only applicable to the pipeline with the nominal diameter of DN80. Loose flange connection is actually achieved by welding, but this kind of flange is loose tube in the affiliated with the pipe welding components, and then by connecting bolts to the accessory components and pressure to achieve sealing gasket, flange (that is, loose tube) itself is not contact medium. The attached components and tubes are welded in both flat and butt welding. This flanged connection is a bit of a flange that can be rotated, easily aligned to the bolt hole, and is easy to install on a large diameter pipe. Loose sets of flanges also apply to places where the pipe needs to be removed frequently for cleaning or inspection, or to rotate the flange without rotating the pipe when the flange bolt hole is used. When using this kind of flange joint, flange ancillary components and pipe material is consistent, and flange material can be different from the pipe material, thus is applicable to transport corrosive medium in the pipeline and non-ferrous metal pipeline system, to achieve the purpose of save expensive material as far as possible. Loose flanges can be divided into two kinds of loose flange, such as the loose flange of welding ring, loose flange of butt welding ring, loose flange of flat welding ring and loose flange of flanged ring. Manager of wenzhou qiang industrial pipe flanging co., LTD Common franking cover type: There are five kinds of surface, convex surface, concave convex surface, mortise surface and ring joint surface. Plane FF Plane sealing is mainly used for the width of the flange and low pressure pipeline system, and the suitable sealing gasket contact distribution Yu Falan bolts inside and outside the quantity side of the center circle, the corresponding gasket material more non-metallic soft material, such as asbestos rubber gasket preloaded pressure is low Tu surface RF Tu face sealing surface is mainly used in the narrow face of the flange, namely the gasket contact area is located in the flange bolt hole surrounded by a circular range, namely tu face seal face coincide with the corresponding gasket diameter flange bolt inscribed circle diameter, can use when installation bolt fixed in the position of gasket in the middle of the flange surface. This sealing surface is widely used in flanges. Concave convex surface MF (M surface and FM surface) The feature of the concave convex sealing surface is that the gasket is embedded in the concave of the concave surface, reducing the possibility of the gasket being impacted by the pressure, and it is easy to assemble when assembling. Compared with tu face seal face of the flange, the sealing surface can often be used in a strict sealing occasions, its shortcomings are two pair of flange sealing surface, sealing surface machining the complex surface of flange, so not as widely used as tu face of the flange. Compared with the mortise flange, it has the disadvantage of not protecting the gasket from the pipe. The sealing gasket of the concave convex sealing surface is: various kinds of non-metal flat mat, bag, basic type or the inner and outer ring type winding pad. Grooved surface TG The sealing surface has the advantages of similar to the concave and convex surface of the flange and is superior to the concave and convex surface of the flange, the gasket is located in the ring grooves, restricted by the metal wall on both sides, from the gasket compression deformation were packed into the pipe. Because the gasket is not in direct contact with the internal fluid medium, it is less subjected to corrosion or corrosion of the fluid medium, so it can be used for high pressure, inflammable and explosive, toxic media, etc. The sealing gasket installed good to neutral, but the sealing surface processing is difficult, replacing gasket sealing face easy injury, and to be in when to install and remove the axial separate flange, so when fitting design should consider there are separate flange in axial. Ring surface RJ The flange of the ring seal pad is also a narrow flange. And make a ring on the flange of the trapezoidal channel as flange sealing surface, and the surface of the mortise flange, the flange must in axial when install and remove separate flange, therefore, should be considered in the design of the pipeline to separate flange in axial. This sealing surface is specially designed for metal materials to be processed into the shape of an octagonal or oval-shaped solid metal gasket for sealing connection. Due to the metal ring cushion can according to the intrinsic characteristics of various metals, and the sealing surface of the sealing surface sealing performance is good, also not too strict with installation, suitable for high temperature and high pressure condition, but the sealing surface of the machining accuracy is higher.