The welded steel pipe used for conveying low-pressure fluids is also called a general welded pipe, commonly known as a black pipe. It is a welded steel pipe used for the transportation of water, gas, air, oil and heating steam, and other generally lower pressure fluids and other uses. The wall thickness of the steel pipe is divided into ordinary steel pipe and thick steel pipe; the pipe end is divided into non-threaded steel pipe (light pipe) and threaded steel pipe. The welded steel pipe used for low-pressure fluid transportation is not only directly used for conveying fluids, but also used as a raw pipe for galvanized welded steel pipes for low-pressure fluid transportation.
Q345C high frequency erw steel pipe
1. Galvanized welded steel pipe for low-pressure fluid delivery, also known as galvanized welded steel pipe, commonly known as white pipe. It is a hot-dip galvanized welded (furnace or welded) steel pipe for general low pressure fluids such as water, gas, air oil, heating steam, and warm water. The wall thickness of the steel pipe is divided into ordinary galvanized steel pipe and thick galvanized steel pipe; the pipe end is divided into non-threaded galvanized steel pipe and threaded galvanized steel pipe. The specification of the steel pipe is expressed by the nominal diameter (mm), and the nominal diameter is the approximate value of the internal diameter. Commonly used in inches, such as 1/2, 3/4, 1,2 and so on.
2. Ordinary carbon steel wire bushings are used to protect electrical wires in electrical and industrial installations such as industrial and civil buildings and installation machinery and equipment.
3. Straight seam welded steel pipe is a longitudinally parallel steel pipe of the weld. Used for general structure, usually divided into metric welded steel pipe, welded thin wall pipe and so on.
The following is a description of the main production process for the large diameter straight seam welded pipe for the forming process of the pipe:
1. Striking: After the steel plate used for manufacturing large-diameter submerged-arc welded straight-joint steel pipes enters the production line, full-plate ultrasonic inspection is first performed;
2. Milling edge: Through the edge milling machine, the two edges of the steel plate are double-sided milled to achieve the required plate width, plate edge parallelism and groove shape;
3. Pre-bend: Pre-bending machine for pre-bending the edge so that the edge of the board has a curvature that meets the requirements;
4. Forming: Firstly, half of the pre-bent steel plate is stamped and stamped into a “J” shape on a JCO forming machine. The other half of the steel plate is also bent and pressed into a “C” shape to form an opening. “O” shaped 16Mn welded steel pipe
5. Pre-welding: After the formation of straight seam welded steel pipe joints and continuous welding using gas shielded welding (MAG);
6. Internal welding: Use vertical multi-wire submerged arc welding (up to four wires) to weld inside the straight seam steel pipe;
7. Outer welding: Use vertical multi-wire submerged arc welding to weld outside LSAW steel pipe;
8. Ultrasonic inspection I: Inspect the internal and external welds of the straight seam welded steel pipe and the base metal on both sides of the weld;
9. X-ray inspection I: X-ray industrial television inspection of the internal and external welds of 100, the use of image processing systems to ensure detection sensitivity;
10. Expanded diameter: Expand the entire length of the ssaw steel pipe to increase the dimensional accuracy of the steel pipe and improve the distribution of internal stress in the steel pipe.
11. Hydraulic pressure test: The root diameter of the expanded steel pipe is tested on the hydrostatic testing machine to ensure that the steel pipe meets the required test pressure. The machine has automatic recording and storage functions;
12. chamfering: After passing the inspection, the steel pipe is processed by the pipe end to reach the required pipe end groove size;
13. Ultrasonic inspection II: Ultrasonic inspection is performed one by one again to check the Q345B thick-walled welded steel pipe that the straight seam welded steel pipe may produce after expanding and water pressure, and the manufacturer;
14. X-ray examination II: X-ray industrial television inspection and tube-end weld seam inspection of steel tubes after diameter expansion and hydrostatic pressure testing;
15. Tube end magnetic particle inspection: perform this inspection to find the tube end defects.