Large-diameter steel pipes have won unanimous praise from consumers in their application. They are widely used in mechanical parts, fluid transportation, construction sites, etc. Large-diameter steel pipes have undergone strict inspections during manufacturing, which improves their durability. Large-diameter steel pipes have high dimensional accuracy and smooth inner and outer surfaces. There is no oxide film on the inner and outer surfaces of the steel pipes after heat treatment. There are no cracks in the expansion and flattening of steel pipes, and no deformation in cold bending. They can withstand high pressure and can be used for various complex deformations and mechanical processes. Deep processing.

Expression of large diameter steel pipe diameter:

1. For water and gas transportation steel pipes (galvanized or non-galvanized), cast iron pipes, and other pipes, the pipe diameter should be expressed in nominal diameter DN;

2. For pipes such as seamless steel pipes, welded steel pipes (straight seam or spiral seam), copper pipes, stainless steel pipes, etc., the pipe diameter should be expressed as outer diameter × wall thickness;

3. For pipes such as reinforced concrete (or concrete) pipes, clay pipes, acid-resistant ceramic pipes, cylinder tile pipes, etc., the pipe diameter should be expressed by the inner diameter d;

4. For plastic pipes, the pipe diameter should be expressed according to the product standard method;

5. When the design uses the nominal diameter DN to express the pipe diameter, there should be a comparison table between the nominal diameter DN and the corresponding product specifications.

Methods for processing large diameter steel pipe fittings:

1. The price of large-diameter steel pipe fittings is divided into forging, stamping, rolling, rolling, bending, expansion, and other methods. Several processing methods are now introduced as follows:

2. Bending and forming method of large-diameter steel pipe fittings: There are three commonly used methods, one method is called the stretching method, the other method is called the stamping method, and the third roller method has 3-4 rollers, two fixed rollers, and one Adjust the roller and adjust the fixed roller distance, and the finished pipe fitting will be curved.

3. Large-diameter steel pipe stamping method: Use a tapered core on a punch to expand the pipe end to the required size and shape.

4. Roller method for large-diameter steel pipe fittings: Place a core inside the pipe and push the outer circumference with a roller for round-edge processing.

5. Large-diameter steel pipe fittings forging method: Use a swage forging machine to stretch the end or part of the pipe to reduce the outer diameter. Commonly used swage forging machines include rotary type, connecting rod type, and roller type.

6. Large-diameter steel pipe rolling method: generally does not require a mandrel, and is suitable for the inner round edge of thick-walled pipes.

7. Bulging method for large-diameter steel pipe fittings: One is to place rubber inside the pipe, and use a punch to compress it above to make the pipe bulge into shape; the other method is hydraulic bulging, in which liquid is filled into the middle of the pipe, and the liquid pressure bulges the pipe. into the required shape. This method is mostly used in the production of corrugated pipes.