Large diameter spiral steel pipes are different from LSAW steel pipe and are easy to understand. The lining plastic pipe is a steel-lined plastic composite pipe. It is based on ordinary carbon steel pipe and is lined with chemically superior thermoplastic. It is cold drawn or composited by rotational molding. It has both mechanical properties of steel pipe and corrosion resistance of plastic pipe. It is a good pipeline for transporting acid, alkali, salt, corrosive gas and other media.
The square tube is a hollow square section light-thin wall steel pipe, and the steel pipe for building bridge is also called steel refrigeration bending material. It is made of Q235 hot-rolled or cold-rolled strip or coiled steel as the base material after cold bending and then high-frequency welding to make square section shape size steel.
In addition to the thickening of the wall thickness of the hot-rolled thick-walled square pipe, the corner size and the straightness of the edge are both up to or exceed the square of the resistance welding cold-forming square. High precision angles make high quality carbide molds as well as professional molders. Make sure the tolerances are accurate and uniform.
Smooth surface: The advanced cold extrusion process makes the surface of cold drawn steel products smooth and bright. The shape and specification are diverse. By designing different shapes of molds, cold drawing different cross-sectional shapes, cold-drawn steel with different specifications and tolerances, the angle can be designed as a right angle or a rounded corner.
LSAW steel pipe for building bridges Hot-dip galvanized steel pipes are obtained by reacting molten metal with an iron matrix to produce an alloy layer, thereby combining the substrate and the plating layer. Hot-dip galvanizing is to pickle the steel pipe first, in order to remove the iron oxide on the surface of the steel pipe, after pickling, it is washed by ammonium chloride or zinc chloride aqueous solution or a mixed aqueous solution of ammonium chloride and zinc chloride, and then fed. Hot dip plating tank.
Hot-dip galvanizing of steel pipes for building bridges has the advantages of uniform plating, strong adhesion and long service life. The steel pipe matrix and the molten plating solution undergo complex physical and chemical reactions to form a corrosion-resistant structure of a zinc-iron alloy layer. The alloy layer is integrated with the pure zinc layer and the steel pipe base. Therefore, its corrosion resistance is strong.
1. Uniformity of galvanized layer: Steel pipe sample is continuously immersed in copper sulphate solution for 5 times without reddening (copper plating) steel pipe for building bridge
2. surface quality: the surface of the galvanized steel pipe should have a complete galvanized layer, there must be no black spots and bubbles that are not plated, allowing for a rough surface and local zinc.
The surface of the galvanized steel pipe is welded with hot dip or galvanized steel. Zinc plating can increase the corrosion resistance of steel pipes and prolong their service life. The use of galvanized pipes is very wide. Steel pipes for building bridges There are four spiral submerged arc welded pipe production lines in spiral steel pipe plant, all of which use today’s advanced production equipment and American Lincoln automatic submerged arc welding machine, and are equipped with steel pipes for building bridges.
Online digital ultrasonic flaw detector, hydrostatic testing machine, X-ray real-time imaging, universal material testing machine, Charpy material impact testing machine and other complete quality inspection instruments. The company’s products have been tested by the “Special Quality Supervision and Inspection Center for Petroleum Industry” and all of them have reached the standard. In 2007, the company newly built a large-diameter ultra-thick-wall double-wire double-sided submerged arc welded pipe production line, which can provide users with spiral steel pipes.
The anti-corrosion method of spiral welded steel pipe is generally coated with anti-corrosion. The anti-corrosion coating is uniformly and densely coated on the surface of the rust-removed metal pipe to isolate it from various corrosive media, which is the basic of anti-corrosion steel pipe. One of the methods. Steel pipe anti-corrosion coatings are increasingly using composite materials or composite structures. These materials and structures should have good dielectric properties, physical properties, stable chemical properties, and a wide temperature range.