In coastal works, construction works and pipelines, most of them use galvanized steel pipes. Especially in areas where oil and gas are transported, exposed to chemicals or substances that are easily corrosive to materials. So what is galvanized steel pipe? What’s the difference with black steel pipe? Is it rusted? Find the detailed answer right here.
1. What is Galvanized Steel Pipe?
Galvanized steel pipe is a carbon steel pipe coated with a protective layer of zinc on the surface through electrolysis or ống thép mạ kẽm hot dipping. The thickness of the zinc coating is controlled and adjusted appropriately according to the specifications of the product line.
2. Advantages of galvanized steel pipe
The galvanized layer acts as a protective layer, a barrier against corrosion so that the pipe can be exposed to external environmental factors. As a result, galvanized steel pipes possess outstanding advantages such as:
Good anti-corrosion, no rust: The galvanized layer protects the alloy part from corrosive effects such as chemicals, water, weather, etc., creating corrosion resistance, anti-rust effective for the project.
Durability, good rigidity: High hardness steel pipe, combined with the superior protective effect of the zinc coating on the outside, creates a product with outstanding durability.
No time consuming coating coating processing: Galvanized zinc layer is highly aesthetic with good glossiness, can be directly used for the project without further processing.
Low maintenance costs: Galvanized steel pipes have outstanding durability, van gang long life, less damage, saving a lot of costs for businesses when maintaining works.
Easy to install: Uniform size, automatic aperture cutting and punching according to customer requirements, making the installation process easy and fast.
The cost of materials is not high, the price is competitive, the quality of the product is much larger than the cost of the product.
However, galvanized steel pipes still have some disadvantages that businesses should note:
Galvanized corrugated iron pipes in Vietnam are mainly welded steel pipes, so the hardness and durability are not as high as black steel pipes;
Product cost compared to black steel pipe is somewhat higher.
The contractor needs to consider the specific requirements on each part of the work to choose the appropriate construction material.
3. Galvanized steel pipes
Based on production methods and product characteristics, galvanized steel pipes are divided into 2 main types.
3.1 Galvanized Galvanized Steel Pipe
This is a type of steel pipe where the galvanizing process is carried out before welding into the complete steel pipe.
Raw steel is dipped in a solution containing zinc alloy. Use electrolysis to make zinc ions adhere to the surface of the steel plate. The layer is dense (ranging from 12 to 27 µm) and has no organic matter.
Galvanized steel pipe has good corrosion resistance. However, the galvanized layer is thin, if used for a long time, the pipe may still rust. Therefore, electrolytic galvanized corrugated iron pipes are not used as clean water pipes for drinking and coal gas pipes.
The smooth tube surface should be used in the production of small parts requiring precision plating. Such as screws, Machine manufacturing, electronics, precision instruments, chemicals, light industry, transportation, weapons, aerospace, atomic energy, etc. in the national economy mean great meaning.
3.2 Hot dipped galvanized corrugated iron pipe
This type of steel pipe is coated with galvanized zinc by dipping into a bath of molten zinc at 500 ℃. The zinc dipping process is done after the product has been shaped. The thickness of the galvanized layer ranges from 40-80 µm depending on the pipe section standards.
Compared with ordinary galvanized corrugated iron pipes, hot-dip pipes have a thicker layer of galvanized zinc, so they have better service life and anti-corrosion performance. According to statistics, the service life of hot-dip galvanized steel pipes is 13 years in heavy industry, 50 years in the ocean environment, 30 years in the city.
They are used as street lamp posts, roofing corrugated iron, bolts, nuts, prefabricated house reinforcement, coastal works, drinking water pipes in residential areas.
5. Application of galvanized steel pipe
In addition to inherent strength, galvanized steel pipes also have good corrosion resistance. Therefore, galvanized pipes are applied to many different types of constructions in life.
Making oil and gas pipelines
Application in construction works near the sea
Application for making construction steel pipes, prefabricated house frames, scaffolding
Domestic water pipes
Normally, hot-dip galvanized steel pipe with good corrosion resistance should be used in the drinking water pipeline system. Electro-galvanized pipes have less corrosion resistance, so they are used as daily domestic water pipes.
Fire protection water pipes