Galvanized Steel Pipe

Galvanization is a process that involves applying a protective coating of zinc to metals like steel or iron. The zinc coating offers protection against rust and corrosion, effectively increasing the durability or longevity of the metal. Baolai provide Hot dipped galvanized steel pipe and pre-galvanized steel pipe to its customers.
Galvanized pipes are widely used. In addition to being used as pipeline pipes for general low-pressure fluids such as water, gas, and oil, they are also used as oil well pipes and oil pipelines in the petroleum industry, especially offshore oil fields, and oil heaters and condensation pipes for chemical coking equipment. Pipes for coolers, coal distillation washing oil exchangers, trestle piles, and support pipes for mine tunnels, etc.

What is Galvanized Steel Pipe?

Galvanized steel pipe is a welded or seamless steel pipe with a hot-dip or electro-galvanized layer on the surface.

Galvanization is a process that involves applying a protective coating of zinc to metals like steel or iron. The zinc coating offers protection against rust and corrosion, effectively increasing the durability or longevity of the metal.

Baolai provide Hot dipped galvanized steel pipe and pre-galvanized steel pipe to its customers.

Standard: BS1387, ASTM A53, ASTM A500, ASTM A106, EN10217, EN 10255, JIS 3444, JIS 3452, ASTM A795

If you need for a range of galvanized steel pipe, please feel free to request a quote from Baolai Steel.

galvanised steel pipe

The process of hot dipped galvanized steel pipe and pre-galvanized steel pipe

hot-dip galvanized steel pipe

Hot-dip galvanized steel pipes processing

Hot-dip galvanised pipes are manufactured by dipping the descaled steel pipe into a zinc solution at around 500°C. The galvanised layer enhances the anti-corrosion properties of the steel pipe and extends the service life of the pipe. Hot dipped galvanized steel pipe is mostly utilized in the transmission of coal, gas, and steam, also used for construction, such as scaffolding, greenhouse, and structure.

Pre-galvanized stele pipes processing

Pre-galvanized steel pipe refers to pipe which was galvanized while in sheet format, thus prior to further manufacturing. After the sheet is sent through the mill to be galvanized it is cut to size and recoiled. The pipe thickness will be minimum 12 µm.

The differences of hot-dip galvanized pipes and pre-galvanized pipes

1.Raw material

The processing technology of pre-galvanized steel pipe differs from that of hot-dip galvanizing mainly in the raw materials used. The raw materials of pre-galvanized steel pipes are mainly galvanized steel coils. After the factory processes the galvanized coil into a steel pipe, it is no longer necessary to galvanize again, and it is only necessary to supplement zinc on the welded part. 

2.Coating comparison

The two different galvanizing processes appear as a difference in the thickness of the zinc layer and the effect of use.

Coating thickness

Both methods result in a uniform thickness for the coating. However, the hot-dipped galvanization produces a thicker layer of protection than the pre-galvanization does. The minimum average thickness of hot-dip galvanized steel is of 45-85μm while it is between 20 and 30 μm for the pre-galvanized products.

pre-galvanized steel pipe

Effectiveness

Hot-dip galvanizing is descaling and galvanizing after the steel pipe is produced, the zinc layer is thicker and has continuity, so the corrosion resistance and abrasion resistance are better.
Pre-galvanized steel pipe is galvanized and cut and welded as needed before the steel pipe is produced, there is no zinc layer on the welds and the zinc layer is thinner, so the corrosion resistance is not as good as hot-dip galvanized steel pipe. The advantage of pre-galvanizing is that the zinc layer is more uniform and the appearance is more beautiful. 

3.Price comparison

Because the pre-galvanized steel pipe is directly welded, the hot-dip galvanized steel pipe needs to be processed on the basis of the bare pipe. Therefore, the processing cost is much higher than that of the pre-galvanized steel pipe. 

So when the project does not require high corrosion resistance and quality, people will use pre-galvanized pipe instead of hot-dip galvanized steel pipe.

4.Application

The pre-galvanizing process is favored by people because of its low plating cost, excellent protection properties and beautiful appearance, and is widely used in construction, machinery, solar energy and other fields.

hot-dip galvanized steel post

Due to the better anti-corrosion properties and quality of hot-dip galvanized steel pipe, some projects have to choose Hot Dipped Galv.Pipes, which mainly used in transmission of coal gas, steam & construction