Welded steel pipe, also known as welded pipe, is a steel pipe made of steel plate or steel strip after crimping and welding. Welded steel pipe has a simple production process, high production efficiency, many varieties and specifications, and less equipment investment, but its general strength is lower than that of seamless steel pipe. Since the 1930s, with the rapid development of continuous rolling production of high-quality strip steel and the advancement of welding and inspection technology, the quality of welds has been continuously improved, and the varieties and specifications of welded steel pipes have increased day by day and replaced seamless steel pipes in more and more fields. Seam steel pipe. Welded steel pipes are divided into straight seam welded pipes and spiral steel pipe welded pipes according to the form of welds.
The production process of straight seam welded pipe is simple, the production efficiency is high, the cost is low, and the development is rapid. The strength of the spiral steel pipe welded pipe is generally higher than that of the straight seam welded pipe, and the welded pipe with a larger diameter can be produced with a narrower billet, and welded pipes with different diameters can be produced with the same width billet. But compared with the straight seam pipe of the same length, the weld length is increased by 30~100%, and the production speed is lower. Therefore, most of the welded pipes with smaller diameters adopt straight seam welding, and most of the large diameter welded pipes adopt spiral welding.
1. Welded steel pipes for low-pressure fluid transportation (GB/T3092-1993) are also called generally welded pipes, commonly known as clarinet pipes. It is a welded steel pipe used for conveying water, gas, air, oil, heating steam, and other general lower-pressure fluids and other purposes. The wall thickness of the steel pipe is divided into ordinary steel pipe and thickened steel pipe; the form of the pipe end is divided into unthreaded steel pipe (light pipe) and threaded steel pipe. The specification of the steel pipe is expressed by the nominal diameter (mm), and the nominal diameter is an approximate value of the inner diameter. It is customary to express in inches, such as 11/2 and so on. In addition to being directly used to transport fluids, welded steel pipes for low-pressure fluid transportation are also widely used as raw pipes for galvanized welded steel pipes for low-pressure fluid transportation.
2. Galvanized welded steel pipe for low-pressure fluid transportation (GB/T3091-1993) is also called galvanized electric welded steel pipe, commonly known as a white pipe. It is a hot-dip galvanized welded (furnace welded or electrically welded) steel pipe used for conveying water, gas, air oil, heating steam, warm water, and other general lower-pressure fluids or other purposes. The wall thickness of the steel pipe is divided into ordinary galvanized steel pipe and thickened galvanized steel pipe; the form of the pipe end is divided into non-threaded galvanized steel pipe and threaded galvanized steel pipe. The specification of the steel pipe is expressed by the nominal diameter (mm), and the nominal diameter is an approximate value of the inner diameter. It is customary to express in inches, such as 11/2 and so on.
3. Ordinary carbon steel wire casing (GB3640-88) is a steel pipe used to protect wires in electrical installation projects such as industrial and civil buildings, and installation of machinery and equipment.
4. Straight seam electric welded steel pipe (YB242-63) is a steel pipe whose weld seam is parallel to the longitudinal direction of the steel pipe. It is usually divided into metric electric welded steel pipe, electric welded thin-walled pipe, transformer cooling oil pipe, and so on.
5. The spiral seam submerged arc welded steel pipe for pressurized fluid transportation (SY5036-83) is made of hot-rolled steel strip coils, spirally formed at a constant temperature, welded by double-sided submerged arc welding, and used for pressurized fluid transportation. Spiral seam steel pipe. The steel pipe has strong pressure-bearing capacity and good welding performance. After various strict scientific inspections and tests, it is safe and reliable to use. The diameter of the steel pipe is large, the transmission efficiency is high, and the investment in laying pipelines can be saved. It is mainly used for pipelines transporting oil and natural gas.
6. Spiral seam high-frequency welded steel pipes for pressurized fluid transportation are made of hot-rolled steel strip coils, spirally formed at room temperature, and welded by high-frequency lap welding. Welded steel pipe. The steel pipe has strong pressure bearing capacity, good plasticity, and is convenient for welding and processing; after various strict and scientific inspections and tests, it is safe and reliable to use, the steel pipe has a large diameter, high transmission efficiency, and can save investment in laying pipelines. It is mainly used for laying pipelines for transporting oil and natural gas.
7. Generally, spiral submerged arc welded steel pipes for low-pressure fluid transportation are made of hot-rolled steel strip coils, spirally formed at normal temperature, and made by double-sided automatic submerged arc welding or single-sided welding. They are used for water, gas, and air. Submerged arc welded steel pipes for general low-pressure fluid transportation such as steam and steam.
8. Spiral seam high-frequency welded steel pipes for general low-pressure fluid transportation are made of hot-rolled steel strip coils, spirally formed at normal temperature, and welded by the high-frequency lap welding method. Spiral seam high-frequency welded steel pipes for general low-pressure fluid transportation.
9. Spiral welded steel pipes for piles are made of hot-rolled steel strip coils, spirally formed at normal temperature, and made by double-sided submerged arc welding or high-frequency welding. They are used for foundation piles such as civil and architectural structures, wharves, and bridges. Use steel pipe.
Post time: Jun-20-2023