Welded steel pipe, also known as welded pipe, is a steel pipe welded with steel plates or steel strips. Welded steel pipe has the advantages of simple production process, high production efficiency, many varieties, and low equipment capital, but the total strength is lower than that of seamless steel pipe. Since the 1930s, with the rapid development and welding of high-quality strip rolling With the advancement of inspection technology, the quality of welding continues to improve, the variety and specifications of welded pipes are increasing, and seamless steel pipes are being replaced by more and more fields. Welded steel pipes that are welded can be divided into straight welded pipes and spiral welded pipes. Simple, high production efficiency, low cost, and rapid development. The strength of spiral welded pipe is generally higher than that of straight welded pipe. Welded pipes of different diameters can be produced under the same billet width. However, compared with straight seam pipe of the same length, the weld The length is increased by 30% and 100% respectively, and the production speed is low. Therefore, most of the small diameter straight seam welded pipes are mostly spiral welded. Next, I want to introduce the type of welded steel pipes.
1. Welded steel pipe can be used for low-pressure fluid transportation, also known as ordinary welded pipe, commonly known as black pipe. Used to transport low-pressure liquid water, air, gas, oil, steam, etc. The wall thickness of the steel pipe connection is divided into an ordinary steel pipe and a thickened steel pipe, which is divided into non-threaded and steel pipe (smooth steel pipe) and threaded steel pipe. The specifications of the steel pipe are expressed by the nominal diameter (Mm), which is an approximate value of the inner diameter. It is customary to use inches, such as 11 inches, 2 inches, etc. Welded steel pipes are used for low-pressure fluids, not only for direct delivery of fluids, but also as raw materials for galvanized welded steel pipes for low-pressure fluids.
2. Galvanized welded steel pipe can be used for low-pressure working fluid delivery, also known as galvanized welded steel pipe, commonly known as white pipe. It is used to transport general low-pressure fluids such as water, gas, gas and oil, such as heated steam, warm water or other hot-dip galvanized welded steel pipes (electric furnace welding or electric welding). The steel pipe wall is divided into ordinary galvanized steel and galvanized thick steel, galvanized steel and non-threaded galvanized steel plate. The specifications of the steel pipe are expressed by the nominal diameter (Mm), which is an approximate value of the inner diameter. Usually use inches, such as 11×2.
3. Ordinary carbon steel sleeve is a protective sleeve for industrial and civil buildings, installed wire machinery and other devices and electrical installation.
4. Straight seam welded steel pipe is a kind of steel pipe parallel to the longitudinal research of steel pipe, which can usually be divided into steel pipe in the metric welding process, welding material thin-walled steel pipe, and transformer cooling pipe.
5. Spiral submerged arc welded steel pipe is a spiral welded steel pipe that uses hot-rolled strip as the tube blank, which is often formed at a temperature. Double-sided submerged arc welding is used for pressure fluid transportation. The steel pipe has strong bearing capacity and good weldability. After various strict scientific and technical tests and experiments, the use is reliable. Mainly used for pipeline transportation of oil and natural gas.
6. Spiral seam high-frequency welded steel pipe for pressure fluid transportation is a spiral seam high-frequency welded steel pipe, which is welded by high-frequency lap welding method, and hot-rolled steel coil is often used as a tube blank. Strong bearing steel and plastic to facilitate the welding process. After various strict scientific inspections and tests, it is reliable to use and is mainly used for the laying of oil and gas pipelines.
7. The spiral submerged arc welded steel pipe for low pressure transportation is a hot-rolled strip steel as a small billet, the spiral submerged arc welded steel pipe is a room temperature spiral low-pressure conveying steel pipe, and the hot-rolled steel strip is a pipe blank, which is used for water, gas, steam, etc. Low pressure fluid delivery.
8. The spiral seam high-frequency use welded steel pipe for general low-pressure fluid work transportation is mainly formed by hot-rolled strip as the tube blank at room temperature. A high-frequency lap method is used to weld the high-frequency welded steel pipe to the spiral weld seam. Both are used for low-pressure fluid delivery.
