What factors determine the service life of large blind flange

Due to the high viscosity and poor chip breaking performance of large blind flange material, it is easy to have chip scratch on the workpiece thread or screw tap chipping in the tapping process of ANSI B16.5 stainless steel Special Pipeline Blind flange, which affects the processing efficiency and thread quality. In order to prolong the service life of tap and improve the quality of thread processing,

　　On the steckel mill, the thermomechanical history of the whole length of the large blind flange changes obviously, especially in the production of the micro large blind flange, which will strongly affect the recrystallization degree, grain growth and precipitation on the finishing mill, and lead to the drastic change of the ultimate microstructure and function of the whole length of the large blind flange. The original geometric shape of the leading part must be maintained during grinding. It is better to use a tap spade grinding machine for grinding. The best way to solve the problem is to customize the tap with shorter base according to the specific requirements of the thread to be machined.

　　Large blind flange taps should be made of better taps. The wear resistance and toughness of tap can be significantly improved by adding special alloy elements to common high speed tool steel. The heat treatment method of cutting tool should be selected reasonably to take into account the hardness and toughness of tap. Increase the front angle of tap properly. However, it should be noted that if the front angle of the tap is too large, it is easy to cause the tap to break the edge and the tapped thread to have multiple edges when withdrawing the cutter. The wear resistance, heat resistance and lubricity of tap can be improved by coating titanium nitride on the surface of tap.

Grade of oil casing custom pipeline

The oil casing custom pipeline is mainly used for the drilling of oil and gas wells and the transportation of oil and gas. It includes oil drilling pipe, oil casing custom pipeline and oil extraction pipe. Oil casing custom pipeline is mainly used to connect drill collar and bit and transfer drilling power. Petroleum casing is mainly used to support the well wall in the process of drilling and after completion, so as to ensure the normal operation of the whole oil well in the process of drilling and after completion. The oil and gas at the bottom of the oil casing custom pipeline are mainly transported to the surface by the pumping tubing.

　　API 5L X42 N80 Seamless Steel Oil Casing Custom pipeline is the lifeline to maintain oil well operation. Due to different geological conditions, the downhole stress state is complex, and the comprehensive action of tensile, compressive, bending and torsional stresses acts on the pipe body, which puts forward higher requirements for the quality of the casing itself. Once the casing itself is damaged for some reason, the production of the whole well may be reduced or even discarded.

　　According to the strength of the steel itself, the oil casing custom pipeline can be divided into different steel grades, namely J55, K55, N80, L80, C90, T95, P110, q125, V150, etc. Different well conditions and well depths lead to different steel grades. In corrosive environment, the casing itself is also required to have corrosion resistance. In the complex geological conditions, casing is also required to have collapse resistance.

How do socket flanges divide pressure levels

　Socket flanges are used in different places, so the pressure level is different to a certain extent. For example, large stainless steel DIN Class300 Forged Carbon Steel Socket Flanges are mainly used in high temperature pipelines in chemical engineering, so the material pressure performance of socket flange is very high.

　　Therefore, customers often require forging socket flanges, because the material after forging increases the density of the organization, but also enhance its pressure bearing capacity.

　　In domestic and international standards, the pressure resistance of large stainless steel socket flanges has clear grade requirements. Large stainless steel socket flanges are generally divided into: PN25, PN6, PN10, PN16, PN25, PN40 and so on. The most commonly used are PN10 and PN16.

　　For example, the design pressure of socket flanges of internal pressure vessel with safety valve should be determined according to the opening pressure of safety valve. The design pressure is equal to or slightly greater than the opening pressure of the safety valve, while the opening pressure of the safety valve is 1.05-1.1 times of the working pressure.

　　Given that the working pressure is 0.8 MPa, the opening pressure of the safety valve can be 0.88 MPa, so the design pressure can be 0.9 MPa. In this way, it is reasonable to choose the material 1C4 of vessel socket flanges with the maximum allowable working pressure of 0.9 MPa at 50 degrees Celsius.

What are the differences between cold forging and hot forging of slip-on flanges?

Cold forging of slip-on flanges is a process of forging at low temperature, and the size of slip-on flanges changes little. When forged below 700 C, less oxide scales are formed and no decarbonization occurs on the surface. Therefore, as long as the deformation energy is within the range of forming energy, cold forging can easily obtain good dimensional accuracy and surface finish. As long as temperature and lubrication cooling are well controlled, warm forging below 700 C can also achieve good accuracy. Cold die forging, cold extrusion, cold upsetting and other plastic processing. Cold forging is a forming process below the recrystallization temperature of the material and a forging process below the recovery temperature. Cold forging has good surface quality and high dimensional accuracy, which can replace some cutting processes. Cold forging can strengthen metal and improve the strength of DIN2502 RF Pn16 Stainless Steel Slip-on Flange.

　　The development of cold forging technology is mainly to develop high value-added products and reduce production costs. At the same time, slip-on flanges is constantly infiltrating into or replacing cutting, powder metallurgy, casting, hot forging, sheet metal forming process and other fields. It can also be combined with these processes to form a composite process.

　　Hot forging of slip-on flanges is: in hot forging, large slip-on flanges with complex shapes can be forged because the deformation energy and resistance are very small. To obtain slip-on flanges with high dimensional accuracy, hot forging can be used in the temperature range of 900-1000 C. In addition, attention should be paid to improving the working environment of hot forging. The life of forging die is shorter than that of forging in other temperature domains, but it has higher freedom and lower cost. The main purpose of hot forging slip-on flanges is to reduce the deformation resistance of metal, thus reducing the forging pressure required for bad material deformation and greatly reducing the tonnage of forging equipment; changing the as-cast structure of steel ingot used for slip-on flanges, recrystallizing in the process of hot forging, the coarse as-cast structure becomes a new structure with fine grains, and reducing the defects of as-cast structure and improving the mechanical properties of steel.

Advantages of galvanized slip-on flange

Galvanized slip-on flange is to strengthen the corrosion resistance of carbon steel slip-on flange by coating a layer of zinc on the surface of the slip-on flange, so as to achieve the purpose of corrosion resistance.

　　The advantages of hot galvanized slip-on flanges are as follows:

　　1.cost paper: the cost of hot dip galvanizing is lower than that of other paint coatings;

　　2.durability: in suburban environment, the standard thickness of hot galvanizing rust-proof can be maintained for more than 50 years without repair; in urban or offshore areas, the standard hot galvanizing slip-on flange coating can be maintained for 20 years without repair

　　3. good reliability: galvanizing coating and slip-on flange. Metallurgical bonding between materials makes the coating a part of the steel surface, so the durability of the coating is relatively reliable

　　4.coatings is strong: the galvanized DIN2502 RF Pn16 Stainless Steel Slip-on Flange a special metallurgical structure, which can withstand mechanical damage in transportation and use; 5. comprehensive protection: every part of the plated part can be galvanized, even in the depression, sharp angle and hidden place can be fully subject to. Protection

　　6. time-saving and labor-saving: galvanizing process is faster than other coating construction methods, and can avoid the time required to brush on the site after installation.

Welding deformation principle of large threaded flange

　According to the principle of deformation during welding of large threaded flange, the influence of welding skill on transverse shortening is analyzed by using low carbon steel and full specification stainless steel. The welding method of selecting section back welding, adding short section or selecting upper thin and lower thick ANSI B16.5 Class 600 Stainless Steel Threaded Flange is put forward. Add sealing points between two threaded flange, and then fasten them with bolts. The first standards are national standards, electric standards, American standards, German standards, Japanese standards, etc.

　　Attention should be paid to improving the working environment of hot forging. Always adhere to the dryness and ventilation of stainless steel large threaded flange, adhere to the cleaning and tidiness of the device, and store it in accordance with the correct storage method. The value in brackets indicates the allowable wall thickness error value of the same large threaded flange on different sections. The distance between the two sections is not more than twice the pipe diameter, and the maximum is not more than 300 mm.

　　Forged large threaded flange connection is easy to use and can bear large pressure. Butt welding is adopted for the connection of large threaded flange and pipeline. The welding seam is similar to the welding of pipeline and pipeline. Generally, argon arc welding is adopted for the small pipe diameter, and double-sided welding is adopted for the large pipe diameter.

General process flow of socket weld pipe fitting

　Forging is one of the two main parts of forging. It is a kind of processing method that uses socket weld pipe fitting machinery to exert pressure on metal blank to produce plastic deformation to obtain socket weld pipe fitting with certain mechanical properties, certain shape and size. Through forging, the defects of loose as cast metal produced in smelting process can be eliminated, and the microstructure can be optimized. At the same time, the mechanical properties of forgings are generally better than those of castings of the same material because of the intact metal streamline.

　　For the important parts with high load and severe working conditions in the related machinery, except for the simple shape of rolled plates, profiles or weldments, Forged Steel High Pressure Socket Weld Pipe Fitting 45 degree elbow are often used.

　　Different forging methods have different processes, among which hot die socket weld pipe fitting process is the longest, and the general sequence is: socket weld pipe fitting blank blanking; forging blank heating; roll forging blank preparation; die forging; trimming; punching; correction; intermediate inspection, inspection of socket weld pipe fitting size and surface defects; forging heat treatment, to eliminate forging stress and improve metal cutting performance; cleaning, mainly to remove surface oxygen Generally, forgings shall be subject to appearance and hardness inspection, and important socket weld pipe fitting shall be subject to chemical composition analysis, mechanical property, residual stress and other inspection and NDT.