Elbow In the piping system, the elbow is a pipe that changes the direction of the pipe. According to the angle, there are three most commonly used 45° and 90°180°, and other abnormal angle elbows such as 60° are also included according to engineering needs. Elbows are made of cast iron, stainless steel, alloy steel, malleable iron, carbon steel, non-ferrous metals and plastics. The way to connect to the pipe is: direct welding (the most common way) flange connection, hot melt connection, fused connection, threaded connection and socket connection. According to the production process, it can be divided into: welding elbow, punching elbow, push elbow, casting elbow, butt weld elbow. Other names: 90 degree elbow, right angle bend, love and bend. Divided by material Carbon steel: ASTM/ASME A234 WPB, WPC Alloy: ASTM/ASME A234 WP 1-WP 12-WP 11-WP 22-WP 5-WP 91-WP911, 15Mo3 15CrMoV, 35CrMoV Stainless steel: ASTM/ASME A403 WP 304-304L-304H-304LN-304N ASTM/ASME A403 WP 316-316L-316H-316LN-316N-316Ti ASTM/ASME A403 WP 321-321H ASTM/ASME A403 WP 347-347H Low temperature steel: ASTM/ASME A402 WPL3-WPL 6 High Performance Steel: ASTM/ASME A860 WPHY 42-46-52-60-65-70 Cast steel, alloy steel, stainless steel, copper, aluminum alloy, plastic, argon leaching, PVC, PPR, RFPP (reinforced polypropylene). 1. Divided by production method can be divided into push, press, forge, casting and so on. 2. According to the manufacturing standards, it can be divided into national standard, electric standard, ship standard, chemical standard, water standard, American standard, German standard, Japanese standard and Russian standard. 3. According to its radius of curvature: can be divided into long radius elbow and short radius elbow. A long radius elbow refers to the outer diameter of a tube whose radius of curvature is equal to 1.5 times, that is, R = 1.5D; a short radius elbow refers to a radius of curvature equal to the outer diameter of the tube, that is, R = 1.0D. (D is the elbow diameter and R is the radius of curvature). 4. According to the pressure level: about seventeen, and the United States pipe standards are the same: Sch5s, Sch10s, Sch10, Sch20, Sch30, Sch40s, STD, Sch40, Sch60, Sch80s, XS; Sch80, SCH100, Sch120, Sch140, Sch160, XXS; the most commonly used are STD and XS. 5. According to different shapes and uses, it can be divided into: grooved elbow, ferrule elbow, double bearing elbow, flange elbow, reducer elbow, dull elbow, inner and outer elbow, punch elbow , push the elbow, socket elbow, butt weld elbow, inner wire elbow, etc. Process flow Seamless elbow: An elbow is a type of pipe used for turning a pipe. Among the total pipe fittings used in the piping system, the proportion is the largest, about 80%. Generally, different forming processes are selected for bends of different materials or wall thicknesses. The seamless elbow forming process commonly used in manufacturing plants has hot push, stamping, extrusion and the like. Hot push forming The hot push elbow forming process uses a special elbow pusher, a core mold and a heating device, so that the blank placed on the mold moves forward under the push of the pusher, is heated, expanded, and bent during the movement. the process of. The deformation characteristic of the hot push elbow is to determine the diameter of the tube blank according to the law of the volume change of the metal material before and after plastic deformation. The diameter of the tube blank used is smaller than the diameter of the elbow, and the deformation process of the billet is controlled by the core mold to compress the inner arc. The flow of the metal compensates for other portions that are thinned by the expansion of the diameter, thereby obtaining an elbow having a uniform wall thickness. The hot-bending elbow forming process has the characteristics of beautiful appearance, uniform wall thickness and continuous operation, and is suitable for mass production. Therefore, it is the main forming method for carbon steel and alloy steel elbows, and is also applied to some specifications of stainless steel elbows. Forming. The heating process of the forming process includes medium frequency or high frequency induction heating (the heating coil can be multi-turn or single turn), flame heating and reverberatory furnace heating, and the heating method is determined by the forming product requirements and energy conditions. Stamping Stamping forming elbow is the earliest forming process for mass production of seamless elbows. It has been replaced by hot pushing or other forming processes in the production of elbows of common specifications, but in some specifications of elbows due to the number of production Less, the wall thickness is too thick or too thin. The product is still in use when it has special requirements. The stamping of the elbow is performed by using a tube blank equal to the outer diameter of the elbow, and is directly press-formed in the mold using a press. Before the stamping, the tube blank is placed on the lower mold, the inner core and the end mold are loaded into the tube blank, the upper mold is moved downward to start pressing, and the elbow is formed by the constraint of the outer mold and the support of the inner mold. Compared with the hot push process, the appearance quality of stamping is not as good as that of the former; when the stamping elbow is formed, the outer arc is in a stretched state, and no other parts of the metal are compensated, so the wall thickness at the outer arc is about 10% thinner. . However, due to the characteristics of single-piece production and low cost, the stamping elbow process is mostly used for the manufacture of small batches and thick-walled elbows. Stamping elbows are divided into cold stamping and hot stamping. Cold stamping or hot stamping is usually selected according to material properties and equipment capabilities. The forming process of the cold extrusion elbow is to use a special elbow forming machine to put the tube blank into the outer mold. After the upper and lower molds are closed, the blank is reserved along the inner and outer molds under the push of the push rod. The gap moves to complete the forming process. The elbow manufactured by the inner and outer mold cold extrusion process has beautiful appearance, uniform wall thickness and small dimensional deviation, so the stainless steel elbow, especially the thin-walled stainless steel elbow forming, is mostly manufactured by this process. The precision of the inner and outer molds used in this process is high; the wall thickness deviation of the tube blank is also demanding. Medium plate welding Use a medium plate press to make half of the elbow profile and then weld the two sections together. Such a process is generally used for elbows above DN700. Other forming methods In addition to the three conventional forming processes described above, the seamless elbow forming process also employs a forming process in which the tube blank is extruded into the outer mold and then passed through the tube blank. However, this process is relatively complicated, the operation is troublesome, and the forming quality is not as good as the aforementioned process, so it is less used. Garmin Battery,Garmin GPS Battery,Garmin Nuvi Battery,Garmin Rechargeable Battery Shenzhen Sunwind Energy Tech Co.,Ltd , https://www.sunwindbatterylm.com
September 04, 2022