Detailed explanation of the characteristics and uses of square and rectangular pipes

Square rectangular pipe is a term for square and rectangular pipes, which refers to steel pipes with equal or unequal side lengths. It is rolled from strip steel through process processing. Generally, the strip steel is unpacked, flattened, curled, and welded into circular tubes, which are then rolled into square tubes and cut to the required length.

Also known as square and rectangular cold-formed hollow steel, abbreviated as square tube and rectangular tube, with codes F and J respectively

1. The allowable deviation of the wall thickness of a square tube shall not exceed plus or minus 10% of the nominal wall thickness when the wall thickness is not greater than 10mm, and plus or minus 8% of the wall thickness when the wall thickness is greater than 10mm, except for the wall thickness in the corner and weld area.

2. The typical delivery length of square rectangular tubes is 4000mm to 12000mm, with 6000mm and 12000mm being the most common. Square rectangular pipes allow delivery of short and non fixed length products not less than 2000mm, and can also be delivered in the form of interface pipes, but the purchaser should cut off the interface pipes when using them. The weight of short and non fixed length products shall not exceed 5% of the total delivery quantity, and for square and rectangular pipes with a theoretical weight greater than 20kg/m, it shall not exceed 10% of the total delivery quantity.

Standard and purpose:

Firstly, galvanized welded square tubes for low-pressure fluid transportation, with standard number GB/T3091-2008. Representative materials include Q235A, Q235BQ345B, etc. Mainly used for transporting water, gas, air, oil, and heating hot water or steam, limited to general lower pressure fluids.

Secondly, galvanized welded square tubes for low-pressure fluid transportation, with standard number GB/T3092-2008. The representative material is the same as above. It is mainly used for transporting low pressure fluids such as water, gas, air, oil, and heating hot water or steam. The surface of the square tube adopts hot-dip galvanizing or cold galvanizing anti-corrosion technology.

Thirdly, welding square pipes for mining fluid transportation, with standard number GB/T14291-2000. The representative material is Q235A, B-grade steel. It is mainly used for straight seam welded square pipes for mine air pressure, drainage, and shaft gas release.

Fourth, large-diameter welded square tubes for low-pressure fluid transportation, with standard number GB/T14980-1994. The representative material is Q235AB grade. Mainly used for transporting low-pressure fluids such as water, sewage, gas, air, heating steam, etc.

Fifth, stainless steel welded square tubes for mechanical structures, with standard number GB/T12770-1991. Representative materials include 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb, etc. Mainly used for mechanical, automotive, bicycle, furniture, hotel and restaurant decoration, as well as other mechanical components and structural parts.

Sixth, stainless steel welded square tubes for fluid transportation, standard number GB/T12771-1991. Representative materials include 0Cr13, 0Cr19Ni9, 00Cr19Ni11, 00Cr17, 0Cr18Ni11Nb, 0017Cr17Ni14Mo2, etc. Mainly used for transporting low-pressure corrosive media.

Seventh, spiral square tubes for low-pressure transmission (standard of the Ministry of Petroleum)? The standard number is SY/T5037-2008. The representative material is carbon steel such as Q235BQ345B. Mainly used for low-pressure transportation of water, oil, natural gas, heating and other pipelines.

Eighth, square tubes are used for transporting flammable and non flammable fluids, with standard number GB/T9711.1 (GB/T9711.2) -1997. The representative material is L245-L415, and steel is used for pipelines. Mainly used for transporting flammable and non flammable fluids with low-pressure or high-pressure square tubes, with relatively high requirements. Mainly used in engineering construction, glass curtain walls, door and window decoration, steel structures, guardrails, machinery manufacturing, automobile manufacturing, home appliance manufacturing, shipbuilding, container manufacturing, electricity, agricultural construction, agricultural greenhouses, bicycle racks, motorcycle racks, shelves, fitness equipment, leisure and tourism products, steel furniture, various specifications of oil casings, oil pipes and pipeline pipes, fluid transportation such as water, gas, sewage, air, heating, fire protection and support, construction industry and other fields.