Comparison of flange materials

 The material of carbon steel flange is not intended to be carbon steel, but we all know that the performance of carbon steel is relatively poor, which is vulnerable to corrosion by external factors, thus affecting the service performance of carbon steel flange. Therefore, carbon steel flange can be put into use only after some treatment during production. Commonly used treatments are mainly divided into metal plating or rust paint.

　　Carbon steel flange is used in a special field, so it requires smooth material and other characteristics. It can be used under high pressure without distortion. Because carbon steel has few burrs, its friction is also very small, which can be more applied to equipment.

Preparations for carbon steel flange measurement

 With the rapid development of domestic and foreign pipeline construction, pipeline pressure test has become an essential and important link. Before and after the pressure test, each section of pipeline must be cleaned by ball cleaning, usually 4 ~ 5 times. Especially after the pressure test, the water stored in the pipeline is difficult to clean, and the cleaning times will be more. Before the measurement of carbon steel flange, it is necessary to make certain preparations, measure according to certain methods and methods, and determine different measurement methods according to specific conditions to ensure the accuracy of measurement.

　　The following describes the preparations for carbon steel flange measurement:

　　1. Before measurement, according to the position of large flange, first draw the sketch of each connecting large flange of the equipment and number it continuously, so that the fixture can be installed according to a certain way and principle, so as to ensure normal use.

　　2. During installation, the carbon steel flange may have different outer diameters, staggered joints (non concentric) and unequal gasket thickness, so the machined fixture shall correspond to the carbon steel flange on the side and cannot be interchanged. Therefore, measuring the size and number of each part is the key to fixture processing and installation

　　3. When measuring, it is best to arrange three people, two of whom measure, one of whom proofreads and fills in the form. The measuring tool is vernier caliper. If there is no condition, external caliper and steel ruler can be used Measurement is a detailed work and the premise of fixture installation. The measurement and record must be prepared without error, and the form must be filled in carefully and clearly In the actual measurement work, we should cooperate with each other and be able to cooperate and use according to the correct principle.

Pure zinc coating of hot dip galvanized steel pipe to improve corrosion resistance

 　Hot dip galvanized steel pipe is made on the basis of ordinary steel pipe. In addition, the zinc coating is well combined with the substrate. In this process, there are many processes and processes. The alloy layer and pure zinc layer on the surface can greatly improve the corrosion resistance of steel pipes.

　　First, the corrosion resistance of hot-dip galvanized steel pipe is relatively high. In humid environment, galvanized pipe must be corrosion resistant. The method of hot galvanizing is not only to improve the quality, but also to continuously strengthen the requirements for corrosivity, so it is more suitable for the construction process.

　　Second, the hot-dip galvanized steel pipe has high strength, good performance and light weight, which are the three advantages that need to be possessed in the construction process

　　Third, hot-dip galvanized steel pipe hot-dip galvanized material is mainly a new process used in steel processing. At present, in the promotion of processing technology, such steel will have good properties. The price in the market is reasonable, which is the key to recognition.

Maintenance method of elbow

 1. Elbows stored for a long time shall be inspected regularly. The exposed processing surface shall be kept clean, dirt shall be removed, and stored neatly in a ventilated and dry place indoors. Stacking or outdoor storage is strictly prohibited. Always keep the elbow dry and ventilated, keep the device clean and tidy, and store it according to accurate storage methods.

　　2. During installation, the elbow can be directly installed on the pipeline according to the connection mode and installed according to the use position. Generally, it can be installed at any position of the pipeline, but it needs to be easy to operate. Note that the medium flow direction of the stop elbow should be upward under the longitudinal valve disc, and the elbow can only be installed horizontally. Pay attention to the tightness of elbow during installation to prevent leakage and affect the normal operation of pipeline.

　　3. When the ball valve, stop valve and gate valve of elbow are used, they are only fully open or fully closed, and are not allowed to adjust the flow, so as to avoid erosion of the sealing surface and accelerated wear. There is a reverse sealing device in the gate valve and upper thread stop valve. The hand wheel is screwed to the top position to prevent the medium from leaking from the packing.

Cause analysis of cracks in pipe bend process

 Cause analysis of cracks during pipe bend process: defects and protection microcracks generated during medium frequency pipe bend. When induction heating pipe bend, microcracks will occur on the outside of the elbow when it exceeds a certain level of deformation temperature and a certain level of deformation. Both of these conditions are related to the material of the pipe bend. Under the similar forming conditions of low deformation speed and high tension resistance, all bending construction of the pipe bend under this condition may produce such data damage.

　　In May, the domestic pipe bend market continued to decline. At the end of the month, there were signs of acceleration due to the broken position of pipe bend processing price. The social inventory of pipe bend continued to be decontaminated, and the Lange composite index closed below the 140 level.

　　As for microcracks, we stop the discussion with grain boundary cracks. According to the forming conditions, the crack length is generally reachable. The cracks mainly occur on the austenite grain boundary perpendicular to the stress direction, so they are also perpendicular to the slag inclusion of the extended pipe. After the welded pipe is bent, the microstructure is recrystallized by heat treatment, so that the microcrack changes into crystal.

What are the principles in the production process of carbon steel elbow

 The carbon steel elbow mainly adopts the polygonal ring shell or the closed polyhedral sector shell with polygonal sections at both ends, which is filled with the interior of the pressure transmission medium. Under the internal pressure, the polygonal section under the internal pressure gradually becomes round and eventually becomes a ring shell. According to the needs, a ring shell can be cut into 90 degree elbows, 4 or 6 60 degree elbows or other standards. This process is suitable for making elbows. The ratio of length to diameter is greater than 1.5, which is the manufacturing method of large elbows.

　　Set the pressure and flow of water in front of the carbon steel elbow to be the same, and the pressure loss will occur when the water flows through the pipe. If the loss is greater, the pressure out of the elbow will be smaller, 90DEG; The bend is equivalent to two 45DEG elbows. If the radius of the bend is the same, that is, the impact of the water rushing out of the elbow on the ground will be smaller.

　　Now, the frequency of using carbon steel elbow in various pipelines is also higher and higher, and people gradually begin to pay attention to the price. Under such circumstances, we see more opportunities. It is also this situation that enables the development of carbon steel elbow, and the momentum of development is very good. The carbon steel elbow still has great characteristics. For example, as long as the raw materials are flat plate and developable surface. The accuracy is simple and easy to install and weld.

Application of flange in different fields

 Stainless steel flanges will not produce corrosion, pitting, corrosion or wear. Stainless steel is also one of the strongest building metal materials. Because stainless steel has good corrosion resistance, it can make structural parts permanently maintain the integrity of engineering design.

　　Chrome stainless steel flange also integrates mechanical strength and high extensibility, which is easy to process and manufacture parts, and can meet the needs of architects and structural designers.

　　All metals react with oxygen in the atmosphere to form an oxide film on the surface. Unfortunately, the iron oxide formed on ordinary carbon steel continues to oxidize, expanding the corrosion and finally forming holes. The carbon steel surface can be guaranteed by electroplating with paint or oxidation resistant metals (e.g. zinc, nickel and chromium), but as is known, this protection is only a thin film.

　　Application field of stainless steel flange: stainless steel flange is widely used in petroleum, chemical industry, nuclear power station, food manufacturing, construction, shipbuilding, papermaking, medicine and other industries. It is used differently in different industries and shows its value in various industries.