What is the difference between welded pipe and galvanized steel pipe?

What is the difference between welded pipe and galvanized steel pipe?

Steel pipes are often used in engineering construction. There are many types of steel pipes. Among them, welded steel pipes and galvanized steel pipes are used more. What's the difference between the two? What problems should be paid attention to during construction?

1) The difference between welded steel pipe and galvanized steel pipe

1. Define the difference

Welded steel pipes are made by bending steel strips (or steel plates) before welding, and seams are visible on the surface, while galvanized welded pipes are welded.
Galvanized on a steel pipe basis. The purpose is to galvanize the general steel pipe (black pipe) to improve the corrosion resistance of the steel pipe.

Welded steel pipe and galvanized steel pipe

2. Classification differences

Welded steel pipes are divided into arc welded pipes, high frequency, gas welded pipes, furnace welded pipes, etc., and can be divided into straight seam and spiral according to the shape of the weld. Galvanized steel pipes are only divided into cold-galvanized pipes and hot-dip galvanized pipes. The hot-dip galvanized galvanized layer is thick, and the cost of electro-galvanized is low. Galvanized steel pipes are much more expensive than welded steel pipes.

3. Appearance difference

There is usually a layer of metal material on the surface of galvanized steel pipe, which is generally very smooth and uniform in color. Because the welded steel pipe is relatively simple and rough in production and has a bad appearance, some people call it a clarinet pipe. If you want to buy decorative building materials of these two raw materials, people generally prefer galvanized steel pipes.

4. Differences in usage

Electric welded steel pipes are often used in machinery or petroleum drilling and production industries, water and gas pipes, etc., large-diameter straight seam welded pipes are used for high-pressure oil and gas transportation, etc., and spiral welded pipes are mostly 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 welding steel pipes

1. The raw materials such as steel are inspected first, and only after passing the inspection can they enter the construction site.
2. Check whether the welding materials are qualified and store them according to regulations. Pay attention to whether there is rust on the surface of the welding material. If the steel pipe has been rusted or moldy, it cannot be used.
3. Do a good job in the cleaning management of the welding area, keep the welding area clean and dust-free, without water, oil, rust and other dirt, to prevent weld trauma.
4. Select the welding method, try welding first, and then apply the welding principle. In order to avoid welding quality accidents caused by improper use of welding wire.
5. Check the groove size before pre-welding. Pay attention to check whether the gaps, blunt edges, etc. meet the process requirements.
6. The welder should clean up the slag first when repairing the welding work, and check whether the joint has been processed. There should be no oil, rust and other dirt on the groove.

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