Welded Steel Pipe

Welded Steel Pipe is a steel pipe whose straight weld seam is parallel to the longitudinal direction of the steel pipe, also known as a straight seam steel pipe, which is made by bending a steel plate or strip and then welding the joints. The production process of welded steel pipe is simple, the wall thickness is uniform, the production efficiency is high, the cost is low, and its specification can be adjusted flexibly to meet the requirements of different pipe diameters, so it develops rapidly and is often used in various industrial production and urban pipeline construction.

Welded steel pipe has high strength, toughness and durability, and can effectively bear various loads. It also has good flexibility and impact resistance, and can be used in various building structures. The main advantages of welded steel pipe are as follows:
1. High strength: Welded steel pipe is made of heat-treated metal, and its compressive capacity is generally above 30MPa.
2. Strong toughness: Welded steel pipes can withstand large-span loads without being broken; while traditional welded steel pipes are often easily corroded or deformed and cracked due to long-term use, and cannot resist impact.
3. Good durability: the service life of welded steel pipe is much longer than that of traditional welded steel pipe, and its service life can reach 50 years.
4. Elegant appearance: the welded steel pipe has an elegant appearance and is easy to manufacture.

The use of welded steel pipe
Welded steel pipe are mainly used in water supply projects, petrochemical industry, chemical industry, electric power industry, agricultural irrigation, and urban construction in China.
1. Used for liquid transportation: water supply and drainage;
2. For gas transportation: gas, steam, liquefied petroleum gas;
3. For structural purposes: piling pipe;
4. For bridges: wharfs, roads, building structures, etc.

Under the rapid development of urbanization, welded steel pipe occupy a very important position, such as pipeline projects such as natural gas, bridges, marine output, piling and steel structures, etc., have outstanding contributions, especially in steel structures, in construction Construction sites, construction sites, etc. play different roles.

Welded steel pipe as an important steel pipe, longitudinal welded pipe carries the transportation tasks of many important projects. The following are the current standards of some countries that are commonly used:

GB standards: 

The national standards implemented in China are GB/T 13793-2016 "Straight Seam Electric Welded Steel Pipes" and GB/T 3091-2015 "Welded Steel Pipes for Low Pressure Fluid Transmission".

ASTM Standards: 

The American Society for Testing and Materials has developed many standards for straight welded pipe. These include ASTM A53 "Ordinary and Machining Carbon Steel Longitudinal Welded Pipe", ASTM A106 "Seamless Carbon Steel Straight Welded Pipe", ASTM A252 "Spiral Seam Longitudinal Welded Pipe" and so on.

British Standard: 

BS EN 10217-1:2019 "Technical delivery conditions for welded steel pipes - Welded steel pipes for non-alloy steel pipes".

Japanese Standard: 

JIS G 3452:2019 "Carbon Steel Pipe", which specifies carbon steel straight seam welded steel pipes for general purposes.

These standards stipulate the size, material, manufacturing process, chemical composition, mechanical properties, inspection methods and other requirements of welded steel pipe to ensure that the quality and performance of longitudinal welded steel pipes meet the regulations.

The national standards followed by welded steel pipes are GB/T 13793-2016 "Longitudinal Electric Welded Steel Pipes", GB/T 3091-2015 "Welded Steel Pipes for Low Pressure Fluid Transmission", which stipulates the manufacturing, quality requirements and testing of welded steel pipes method.

National standard for conventional wall thickness welded pipes:

The conventional wall thickness of the national standard for welded pipes of DN15~DN200 is 28mm~5.5mm. 

The national standard wall thickness of DN225~DN300 welded pipes is 4.0mm~7.5mm
The national standard wall thickness of DN350~DN400 welded pipes is 60mm~9.0mm.
The conventional wall thickness of the national standard for welded pipes of DN450~DN600 is 6.0mm~10.0mm.
The conventional wall thickness of the national standard for welded pipes above DN650 is 7.0mm~12.0mm.

The specific allowable error value will be stipulated according to the product requirements and relevant national standards.