Spiral pipe, also known as spiral steel pipe or spiral welded pipe, is made by rolling low-carbon structural steel or low-alloy structural steel strip into pipe blank according to a certain angle of spiral line (called forming angle), and then welding the pipe seam. It can produce large-diameter steel pipe with narrow strip steel.
It is also called a spiral cylinder or a spiral body. The outer diameter of the spiral tube is about 30 nm, the inner diameter is about 10 nm, and the adjacent spiral spacing is about 11 nm. The helix is surrounded by six nucleosomes every week. H1 histone is located on the inner surface of the helix lumen and plays an important role in maintaining the structure of the helix. The 10 nm fibers composed of nucleosomes were spiralized to form 30 nm thick fibers, which further compressed the length of DNA by 6 times.
Spiral pipe features: straight seam welded pipe has the advantages of simple production process, high production efficiency, low cost and rapid development. The strength of spiral welded pipe is generally higher than that of straight seam welded pipe. It can produce welded pipe with larger pipe diameter with narrow blank, and can also produce welded pipe with different pipe diameter with blank of the same width. However, compared with the straight seam pipe with the same length, the weld length increases by 30~100%, and the production speed is low. Therefore, straight seam welding is mostly used for small-diameter welded pipes, while spiral welding is mostly used for large-diameter welded pipes.
Commonly used spiral pipe materials in China generally include: Q235A, Q235B, Q345, L245, L290, X42, X52, X60, X70, X80, 0Cr13, 1Cr17, 00cr19ni11, 1Cr18Ni9, 0cr18ni11nb.
Spiral pipe is mainly used in tap water engineering, petrochemical industry, chemical industry, electric power industry, agricultural irrigation and urban construction. It is one of the 20 key products developed in China. For liquid transportation: water supply, drainage, sewage treatment works, mud transportation, ocean water transportation. For gas transmission: coal gas, steam, liquefied petroleum gas. For structure: as pile driving pipe and bridge; Pipes for wharf, road and building structures, marine piling pipes, etc.
Specification weight table
Calculation formula for meter weight of spiral welded pipe: (outer diameter - wall thickness) * wall thickness *0.0246615