ERW Steel Pipe

　　Pipe straightness is a measure of the amount of bending, pipe diameter deviation, roundness, etc. of the pipe. 　　In the production process, the steel pipe will cause different degrees of curve in the longitudinal direction (that is, the length direction) of the steel pipe body. However, the degree of curve of some steel pipe products can be visually seen by the naked eye, and the steel pipe is not a qualified product. As long as it is a regular manufacturer, such products are absolutely not allowed to leave the factory, and some need special equipment to measure their straightness. 　　The pipe straightness measurement method mainly introduces two kinds, one is the inner hole straightness measurement method, and the other is the online straightness measurement. 　　The inner hole straightness measurement is measured by laser collimation. The basic principle of the straightness detecting device is to use the laser beam as a linear reference object to detect the bending offset and be...

　　Square tube is generally used for structural and maintenance purposes, such as the construction of buildings, railings and signposts. It is measured by its outer dimensions and its thickness, taking the outer walls (which are the same size) and then the wall thickness. 　　The square tube allows easier welding of several tubes, joining their ends. It is also easier to store stacked. 　　The most used materials to manufacture this type of tube are aluminum and steel, although iron is also widely used for its tenacity in structures where the risk of rust is not relevant. They are available in many storage lengths, which normally range from 60 cm to 7 meters, although they can be made to measure. 　　Being an alloy (iron and coal) has many interesting properties. It is a material heavier than aluminum (three times more), so it is especially valued for use in heavy structures and / or that require resistance to corrosion and extreme temperatures, such as the construction of both houses ...

　　According to different forming methods, seamless tube can be divided into two types: extruded and cold drawn. 　　1. Hot rolling (extrusion): round billet → heating → perforation → three-roll cross-rolling, continuous rolling or extrusion → pipe removal → sizing (or reducing diameter) → cooling → straightening → hydraulic test (or flaw detection) → marking → the raw material for the seamless tube in the warehouse is a round tube blank. The round tube blank is cut into a blank of about 1 m in length by a cutting machine, and sent to the furnace for heating through a conveyor belt. The billet is fed into a furnace and heated to a temperature of approximately 1200 degrees Celsius. The fuel is hydrogen or acetylene. Furnace temperature control is a key issue. After the round billet is released, it is subjected to a through-hole punching machine. 　　The more common perforating machine is a conical roller punching machine. This perforating machine has high production efficiency, good pro...

　　Seamless black steel pipe is made of seamless steel pipe that has not been galvanized. Its name comes from the scaly, dark-colored iron oxide coating on its surface. It's used in applications that don't require galvanized steel. 　　The purpose of seamless black steel pipe is to carry propane or natural gas into residential homes and commercial buildings. So that pipes is manufactured without a seam, making it a better pipe to carry gas. Seamless black steel pipe's strength makes it ideal for transporting water and gas in rural and urban areas and for conduits that protect electrical wiring and for delivering high pressure steam and air. The oil and petroleum industries use black steel pipe for moving large quantities of oil through remote areas. This is beneficial, since black steel pipe requires very little maintenance. Other uses for black steel pipes include gas distribution inside and outside homes, water wells and sewage systems. Black steel pipes are never used fo...

　　1. The welded pipe is made of steel plate welded by high-frequency electric resistance welded pipe (ERW welded pipe), straight seam electric welded pipe (LSAW), spiral welded pipe.In electrical engineering, it is indicated by "SC". It can be used as a water gas pipe or a threading pipe, which is relatively thick. 　　2. The line pipe is also the wire tube, relatively thin, with the "T", can only be used for threading. 　　3. The ERW tube is a “high-frequency resistance welded steel pipe”. It is different from the ordinary welded pipe welding process. The weld is made of the base material of the steel strip body, and the mechanical strength is better than that of the general welded pipe. 　　ERW straight seam steel pipe means electric resistance welding. Resistance welding has the characteristics of high production efficiency, low cost, material saving and easy automation. Therefore, it is widely used in various industrial sectors such as aviation, aerospace, energ...

　　The electric resistance welding time is short and the process is not visible, so during the actual welding process, there will be joint quality of instability caused by the instantaneous voltage fluctuations, current shunt, electrode wear and other factors. Nowadays, the application of resistance welding technology has widespread, so the quality control is extremely important. Over the years, many scholars have proposed various resistance welding quality control methods, below is several mature control method we can apply. 　　1. Constant Current Control 　　This method is applied by comparing the detected welding current with the given value, and regulating the firing angle by using its bias swithcing device so as to adjusting the constant current equal to the given value. The key point is how to capture the constant current control current signal. At present, a current collected by the collecting main core coil sensor detects the welding current from the secondary circuit, which di...

　　The biggest difference thin-wall and thick-wall welded steel pipe is the wall thickness. When the ratio of pipe diameter and wall thickness is less than 20, we called this type of carbon steel pipe as thick-walled welded steel pipe. The thin-wall welded steel pipe is applied for pipeline transmission. However, the thick-wall straight seam pipe is mainly used for petroleum geology drilling pipe, petrochemical cracking tube, boiler tube and pipe for automotive bearings, tractors, aviation etc. In general, it is used in multiple parts of the hollow billet and important channel for bearing large pressure. 　　With the increasing requirement for oil and gas pipeline pressure, the application of steel pipe towards to high grade, large-diameter and thick-wall steel pipe. In order to increase the welding quality and production efficiency, limit the weld slag is significant. During the production of thick-wall straight seam welded pipe, we need to reduce the propability of fusion weld toe cl...