The steel tube has a hollow section, and its length is much larger than that of the steel with diameter or circumference.
According to the production process, it is divided into seamless steel pipe and welded pipe, of which two kinds of seamless steel pipe are hot rolling and cold rolling (drawing). The welded pipe is divided into straight seam welded pipe and spiral seam welded pipe.
Steel pipe is not only used for transporting fluid and powdery solid, exchanging heat energy, manufacturing mechanical parts and containers, but also an economic steel. The use of steel pipe to build structural grid, pillar and mechanical support can reduce weight, save metal 20 to 40%, and realize mechanized construction in factories. The manufacture of road and bridge with steel pipe can not only save steel products and simplify construction, but also greatly reduce the area of protective coating and save investment and maintenance costs.
According to the production method, the steel pipe can be divided into two main categories: seamless steel pipe and slotted steel pipe.
1, seamless steel tubes can be divided into hot rolled seamless pipes, cold drawn tubes, precision steel pipes, hot expansion pipes, cold spinning pipes and extruded pipes according to the production methods.
Seamless steel tubes are made of high quality carbon steel or alloy steel, and are divided into hot rolling and cold rolling (drawing).
2, welded pipes are divided into furnace pipe, electric welding (resistance welding) tube and automatic arc welding pipe because of its different welding technology. Because of its different welding forms, there are two kinds of welded pipe and spiral welded pipe, and the end shape is divided into circular welded pipe and special type (square, flat, etc.) welded pipe.
The welded steel pipe is made of the rolled tube shaped steel plate, which is welded by the seam or spiral seam. In the manufacturing method, it is divided into the welded pipe of low pressure fluid transportation, the spiral seam welded pipe, the direct coil welding pipe, the welding pipe and so on. Seamless steel pipe can be used in various industries such as liquid pressure pipes and gas pipes. Welded pipes can be used for water conveyance pipelines, gas pipes, heating pipes, electrical appliances pipes, etc.
Steel Pipe,Galvanized Steel Pipe,Stainless Steel Pipe,Carbon Steel Pipe HeBei GuangHao Pipe Fittings Co .,LTD (Cangzhou Sailing Steel Pipe Co., Ltd) , https://www.guanghaofitting.com
They are divided into circular, square, rectangular and special-shaped steel tubes according to the section shape.
The material is divided into carbon structural steel pipe, low alloy structural steel pipe, alloy steel pipe and composite steel pipe.
It is divided into pipeline, engineering structure, thermal equipment, petrochemical industry, mechanical manufacturing, geological drilling, and high pressure equipment for use.
Home is expected to continue to use the overall test is not affected
In the future, furniture will not be destroyed after it is sent for inspection, and it can continue to be used. Yesterday, the reporter learned that the National Standard for Limits of Hazardous Substances in Wood Furniture (Revised) has been drafted. According to the new standard, the furniture in the future can be placed in the environmental climate chamber for hazardous substances detection, and the furniture will not be damaged after the inspection. Yesterday afternoon, the National Furniture and Indoor Environmental Quality Supervision and Inspection Center laboratory held an open event. The reporter learned at the scene that at present, the furniture inspection is charged on a per-piece basis, and the cost of testing each piece of furniture is about 500 yuan. The detection method is based on the difference in material composition, sampling separately, and then the sample is placed in standard air for extraction and analysis, and non-destructive detection methods will be added in the future. According to Li Jiguang, deputy director of the National Furniture and Indoor Environmental Quality Supervision and Inspection Center, the center has 11 large-scale environmental climate chambers, the largest 30 cubic meters, the smallest 1 cubic meter, for the overall inspection of furniture. “This method ensures that the furniture will not be destroyed after inspection and can continue to be usedâ€. It is reported that the National Standard for the Limitation of Hazardous Substances in Wood Furniture (revised), which was drafted by the Center, has been completed. According to the standard, the furniture can be inspected at a constant temperature and humidity of 23 ° C and a humidity of 45%. Once the new national standard is introduced, sofas, mattresses, etc. can also be non-destructively tested according to this method.