Welded steel pipe, also called welded pipe, is a steel pipe made of steel plates or steel strips that are welded after being curled and formed. The production process of welded steel pipes is simple, the production efficiency is high, there are many varieties and specifications, and the equipment investment is small, but the general strength is lower than that of seamless steel pipes. 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 continued to improve, and the varieties and specifications of welded steel pipes have increased day by day, replacing unfinished steel pipes in more and more fields. Sewing steel pipe. Welded steel pipes are divided into straight seam welded pipes and spiral welded pipes according to the form of the weld.
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 spiral welded pipes is generally higher than that of straight seam welded pipes. Welded pipes with larger diameters can be produced from narrower billets, and welded pipes with different diameters can also be produced from billets of the same width. However, compared with straight seam pipes of the same length, the weld length is increased by 30~100%, and the production speed is lower. Therefore, smaller diameter welded pipes mostly use straight seam welding, while large diameter welded pipes mostly use spiral welding.
1. Welded steel pipes for low-pressure fluid transportation (GB/T3092-1993) are also called general welded pipes, commonly known as black pipes. It is a welded steel pipe used to transport water, gas, air, oil, heating steam and other general lower pressure fluids and other purposes. The wall thickness of steel pipe connections is divided into ordinary steel pipes and thickened steel pipes; the connection end forms are divided into unthreaded steel pipes (plain pipes) and threaded steel pipes. The specifications of steel pipes are expressed in nominal diameter (mm), which is an approximate value of the inner diameter. It is customary to express it in inches, such as 11/2, etc. In addition to being directly used to transport fluids, welded steel pipes for low-pressure fluid transportation are also widely used as the original 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 white pipe. It is a hot-dip galvanized welded (furnace welded or electric welded) steel pipe used to transport water, gas, air oil, heating steam, warm water and other general lower pressure fluids or other purposes. The wall thickness of the steel pipe connection is divided into ordinary galvanized steel pipe and thickened galvanized steel pipe; the connection end form is divided into non-threaded galvanized steel pipe and threaded galvanized steel pipe. The specifications of steel pipes are expressed in nominal diameter (mm), which is an approximate value of the inner diameter. It is customary to express it in inches, such as 11/2, etc.
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 with the weld seam parallel to the longitudinal direction of the steel pipe. Usually divided into metric electric welded steel pipes, electric welded thin-walled pipes, transformer cooling oil pipes, etc.
5. Spiral submerged arc welded steel pipe (SY5036-83) for pressure-bearing fluid transportation is made of hot-rolled steel strip coils as pipe blanks, spirally formed at constant temperature, and welded by double-sided submerged arc welding. It is used for pressure-bearing fluid transportation. Spiral seam steel pipe. Steel pipes have strong pressure-bearing capacity and good welding performance. They have undergone various rigorous scientific inspections and tests and are safe and reliable to use. The steel pipe has a large diameter, high transportation efficiency, and can save investment in laying pipelines. Mainly used for pipelines transporting oil and natural gas.
6. Spiral seam high-frequency welded steel pipe (SY5038-83) for pressure-bearing fluid transportation is made of hot-rolled steel strip coils as pipe blanks, spirally formed at constant temperature, and welded by high-frequency lap welding method. It is used for pressure-bearing fluid transportation. Spiral seam high frequency welded steel pipe. Steel pipes have strong pressure-bearing capacity, good plasticity, and are easy to weld and process. After various strict and scientific inspections and tests, they are safe and reliable to use. The steel pipes have large diameters, high transportation efficiency, and can save investment in laying pipelines. Mainly used for laying pipelines transporting oil, natural gas, etc.
7. Generally, the spiral submerged arc welded steel pipe (SY5037-83) used for low-pressure fluid transportation is made of hot-rolled steel strip coils as pipe blanks, spirally formed at constant temperature, and made by double-sided automatic submerged arc welding or single-sided welding. Submerged arc welded steel pipes are used for transporting general low-pressure fluids such as water, gas, air and steam.
8. Spiral seam high-frequency welded steel pipe (SY5039-83) for general low-pressure fluid transportation is made of hot-rolled steel strip coils as pipe blanks, spirally formed at constant temperature, and welded by high-frequency lap welding. It is used for general low-pressure fluid transportation. Seam high frequency welded steel pipe.
9. Spiral welded steel pipe for piles (SY5040-83) is made of hot-rolled steel strip coils as pipe blanks, which are often heated and spirally formed, and are made by double-sided submerged arc welding or high-frequency welding. They are used in civil construction structures, docks, and bridges. Steel pipes for foundation piles.
Post time: Sep-12-2023