Welded steel pipe
1) The difference between welded steel pipe and galvanized steel pipe
1. Define the difference
Welding.
Galvanized on the basis of steel pipe. The purpose is to galvanize ordinary steel pipes (black pipes) to improve the corrosion resistance of steel pipes.
Welded Steel Pipe VS Galvanized Steel Pipe
2. Classification difference
Welded steel pipes are divided into arc welded pipes, high frequency welded pipes, gas welded pipes, furnace welded pipes, etc. According to the shape of the weld, it can be divided into two types: straight seam and spiral. Galvanized steel pipes are only divided into cold galvanized pipes and hot-dip galvanized pipes. The hot-dip galvanized layer is thick and the cost of electro-galvanizing is low. Galvanized steel pipes are much more expensive than welded steel pipes.
3. Appearance differences
The surface of galvanized steel pipe usually has a layer of metal material, which is generally smooth and well-proportioned in color. Because the welded steel pipe is relatively simple and rough in production, and its appearance is not good, some people call it black pipe. If you want to buy decorative building materials of these two raw materials, people usually prefer galvanized steel pipes.
4. Differences in use
Electric welded steel pipes are often used in machinery or oil drilling industries, water, gas pipes, etc. Large-diameter straight seam welded pipes are used for high-pressure oil and gas transportation, etc. Spiral welded pipes are used for oil and gas transportation, pipe piles, bridge piers, etc. Galvanized welded pipes are more suitable for conveying low pressure liquids.
2) Precautions for welded steel pipes
1. First check the raw materials such as steel and pass the inspection before entering the construction site.
2. Check whether the welding materials are qualified and store them according to the regulations. Pay attention to see if there is rust on the surface of the welding material. If the steel pipe is already rusted or moldy, it will not work.
3. The cleaning of the welding area should be well managed, and the welding area should be kept clean and dust-free, without water, oil, rust and other dirt, to prevent external defects in the welding seam.
4. Select the welding method, first test the welding, and then apply the welding principle. In order to avoid misuse of welding wire to cause welding quality accidents.
5. Check the groove size before pre-welding. Pay attention to check whether the gap, blunt edge, etc. meet the process requirements.
6. The welder should clean up the welding slag before repairing the welding operation to see if the joint is handled well. There should be no oil, rust and other dirt on the groove.
