1. looks from the spiral steel tube. The appearance is to pay attention to those welded joints. The appearance is not a defect and a lack of scale. This can be seen by the naked eye, of course detailed and bilateral theories, using standard models, measurement and magnifying glasses. Because of the appearance of welding defects, this means that the internal spiral tube is very likely to have defects, even if the effort in appearance is not completed, the internal effort is difficult to guarantee.

ASTM A520 Standard Specification for seamless and resistance welded carbon steel pipe products supplementary requirements, for high temperature service, in line with the ISO standard of boiler structure. If the edge steel or stainless steel is used in the manufacture of resistance welded steel pipe according to the requirements of the standard A520, the steel strip should be coiled in a single width and not cut longitudinally except the edge trimming.

The US "Wall Street Journal" disclosed in a report on the 16th that Peter Navarro, director of the White House National Trade Commission, has a close relationship with the US steel industry interest group and has instructed steel companies to provide funds to shoot documentaries supporting their political views.

The quality control of high frequency longitudinal welded pipe is also a key factor to ensure the safety of operators. The main application fields include large span power grid engineering, steel structure engineering construction, electric power and ultrahigh pressure transmission and transmission engineering, mechanical engineering, bridge, bridge, railway station, airport, stadium steel structure, municipal pipe network, foundation pile driving, water gas pipeline and highway construction.

The typical process of high frequency straight welded pipe: open coil - steel strip leveling - head and tail shear - steel strip butt welding - Live sleeve storage - forming welding - cleaning burr - sizing - Test - flying shear - straight pipe processing - water pressure test - printing and coating - finished products.

In all steel pipes, ASTM A53 seamless steel pipe occupies a large proportion, but in actual production, the seamless steel pipe is often used to control rolling and cooling technology. It is easy to control the cooling process caused by the uneven defects of the cooling plate, which seriously affects the quality of the product and the contract cash. The surface wave is one of the more serious ones.

1, the supply of ASTM A53 seamless steel pipe, compared with other traditional pipes, is lighter in raw material, high in strength, good in tolerance, can withstand high internal pressure, is sensitive to production, and can be used in disorderly or abominable geological conditions.

Yonhap News Agency reported on April 4th that South Korea Steel had just won the “232 Survey” in the United States for exemption from customs duties, and immediately faced the EU’s investigation into safeguard measures for iron and steel. The industry expressed great concern. On March 26, the European Union announced that it will carry out investigations on safeguard measures for imported steel products, collect tariffs based on the survey results, or restrict imports in the form of quotas. The survey targets 26 varieties such as cold-rolled steel plates, hot-rolled thick plates, electrical steel pipes, and large-diameter steel pipes. According to the Korean Trade Association on the 4th, the EU’s total steel imports amounted to EUR 57.12 billion last year, of which the amount of imports involved in this safeguard measure amounted to EUR 21.2 billion, while Korea’s exports to the EU involved imports amounting to EUR 2.39 billion (about USD 2.94 billion). ), accounting for 11.3%, higher than the United States "232 investigation" tariff target amount of 2.79 billion US dollars. Some analysts claimed that the EU’s move was intended to prevent the influx of steel products from the world into the EU due to the “232 survey” in the United States. South Korea's steel is more difficult to find alternatives in the face of its blockade of exports to the United States and the European Union.

According to the characteristics of the city's buried sewage pipe, the coating of carbon steel pipes should meet the following basic requirements. (1) good chemical resistance;

The material should be chosen by the coating machine itself, because according to the installation and coating procedures, various materials can be used to meet the minimum requirements for the finished coating specified in this standard. Buyer should agree to any deviation from material use. The surface should be cleaned by sand blasting. Jet cleaning and any neces

Scope between ASTM A53 and ASTM A106 ASTM A53 is Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless. ASTM A106 is Standard Specification for Seamless Carbon Steel Pipe for High-Temperature Service. Application between ASTM A53 and ASTM A106

1, The supply of astm a53 seamless steel pipe compared to other traditional pipe, raw materials lighter, high strength, good tolerance, can withstand high internal pressure, the production of sensitive, and can be used to messy or harsh geological conditions.

As the individual quality of spiral steel pipe is relatively large, it must be stacked in the outdoors, but it will be difficult to avoid the sun and rain, so the problem has been plagued with rust spiral pipe storage time and conditions. Therefore, we need to conduct a comprehensive understanding of the spiral steel pipe rust prevention.

The thermal expansion seamless pipe is a thermal expansion pipe that we often say. Its density is relatively low, but the pipe has very high shrinkage. (Seamless steel pipe) can be called a thermal expansion pipe. A method for expanding the diameter of a pipe by a transverse rolling method or a drawing method; in a short time, the outside diameter of the steel pipe can produce a non-standard and special type of seamless pipe, and the cost is low and the production efficiency is high. It is an international roll pipe field. The development trend.

1, the next thick-walled seamless steel pipe easy to fold. Folding is the formation of a variety of fold lines on the surface of thick-walled seamless steel tubes, which often run through the entire product. The reason for the folding is that due to the pursuit of high-efficiency counterfeit manufacturers, the pressure is too great, the ear is caused, and the next rolling produces wrinkles, the folded product will be broken and bent, and the strength of the thick-walled seamless steel pipe will decrease.

The Costa Rican media "extro" reported in March 25th that if the economic and Commercial Ministry of Commerce (MEIC) approved the increase of steel import tax, the country will face a series of serious consequences. According to CCC's news, last week, the Ministry of economy and Commerce released an open investigation and resolution plan to take protective measures and raise the tariff of steel bars. As steel is the basic material for all kinds of production activities, especially in the construction industry, the association of architects, architectural and engineering consultants and the real estate development commission are firmly opposed to raising tariffs, which will exacerbate the current competitive conditions and may even return to the state of monopoly. Besides, the domestic people will be severely affected by the rising housing costs, which limits the basic rights of families to have decent housing. If the tax is estimated by the Ministry of Commerce and industry and commerce, it may reproduce the plight of steel shortage and high price.

API 5L seamless steel pipe is characterized by its large diameter and relatively thick wall thickness. Therefore, according to this feature, full use of ultrasonic eddy current detection and internal and secondary surface detection functions are combined to achieve a “no blind spot” test. By adopting the “steel tube rotation and detection probe forward combination”, it not only solves the problem of detection of the title, but also solves the space that occupies a narrow space.

Description of API 5L Seamless Steel Pipe Equipment Oil standard: Hydraulic pressure tester prevents oil corrosion after passing through the steel pipe, and marks according to user's requirements.

The use of spiral steel pipe is relatively high, and the application range is very wide. It should be selected before selection and pay attention to quality. The first method is a more professional method of detection by measuring the strength of the pressure vessel. Normally, we use atmospheric pressure and water pressure detection, which can detect the working conditions of spiral steel tubes working under pressure and detect the tightness of spiral steel tubes. Generally, it is measured at atmospheric pressure because the safety is relatively high, if water is used. Vapor pressure passes the test and then the need for a spiral tube under water is too much trouble. The second method is also relatively simple, that is, through the observation surface. Visually find problems with welding and size of spiral steel tubes, and if necessary, compare standard samples with products to find out where the problem lies. In general, the regular steel pipe company is relatively perfect in production, and on the other hand it is necessary to strike the metal pipe. If the sound is very crisp and the echo is not very dirty, then the name is the latest choice of steel pipe, not scrap recycling. Both methods are commonly used. We can choose one method to test. The safer method is the best regular manufacturer, which can reduce the abuse during use.

The spiral steel strip is formed by spiral bending of a steel strip or a spiral plate and is welded on both sides by submerged arc welding. Steel pipes are widely used in water, electricity, chemical industry and other industries for the following reasons.

1. Look from the spiral steel pipe. Appearance should pay attention to those welded joints, to see the appearance is not a drawback, the lack of scale, you can see through the naked eye, of course, detailed and bilateral theory, borrow the standard model, gauges and magnifying glass to view. Due to the occurrence of welding defects, this means that the spiral pipe interior is most likely to have defects. Even if the surface efforts are not yet completed, internal efforts are difficult to guarantee.