Hello, this is MAX the sales manager from TYTSTEEL, I have been in the steel pipe sales industry for ten years With a very rich product knowledge base and export experience, recently a customer asked How to tell the difference between galvanized pipe and black pipe and their respective uses. To help you make the right decision, I’m writing a guide on the difference between galvanized pipe and black pipe, so let’s get started!
Is black pipe the same as galvanized pipe?
No, black pipe and galvanized pipe are not the same; they have distinct differences in terms of material, appearance, and properties.
Black pipe is typically made of steel.
It gets its name from the black or dark-colored iron oxide scale on its surface, which forms during the manufacturing process. This scale provides some protection against corrosion but is not as effective as the galvanization process.
Galvanized pipe is made of steel that has been coated with a layer of zinc through a galvanization process. This process involves immersing the steel pipe in molten zinc to create a protective zinc coating on the surface.
Galvanized pipe is known for its silver or gray appearance due to the zinc coating.
The 3 most important differences between galvanized pipe and black pipe
/ Manufacturing process
Black iron pipe is manufactured by stretching steel into a seamless tube or by pressing the edges together and sealing them with welds.
For galvanized pipe, hot-dip galvanized steel pipe is a steel pipe substrate that undergoes a complex physical and chemical reaction with a molten plating solution to form a corrosion-resistant, tightly structured zinc-iron alloy layer. The alloy layer is integrated with the pure zinc layer and the steel pipe substrate, so the hot-dip galvanized steel pipe has the advantages of uniform coating, strong adhesion, and long service life.
Galvanized pipes are divided into hot-dip galvanized and cold-dip galvanized if the hot-dip galvanized service life is generally not less than 20 years. But the anti-corrosion years are different in different environments: 13 years in heavy industrial areas, 50 years in the ocean, 104 years in the suburbs, and 30 years in the city. Black iron pipes are not coated, so they are less durable.
Generally speaking, galvanized pipes cost much more than black steel pipes. This is due to the zinc coating of galvanized pipe. If you have the budget and durability is not your main consideration, consider choosing black steel pipe over the galvanized pipe.
The primary use of black steel pipe is to transport propane or natural gas to residential and commercial buildings. In transportation, black steel pipe is more corrosive than the galvanized pipe, making it more suitable for transporting gas. Black steel pipe is also used in fire sprinkler systems because it is more fire-resistant than galvanized pipe.
Galvanized pipe has a wide range of uses, in addition to being used as a pipeline pipe for general low-pressure fluids such as water, gas, and oil, it is also used as an oil well pipe and oil pipeline in the petroleum industry, especially in the offshore oil fields, as an oil heater, condensation cooler, and coal distillation and oil washing exchanger pipe for chemical cooking equipment, and as a support frame pipe for trestle piles and mining pits, etc.
Can galvanized pipe be black?
There is a type of pipe in nature that is called “galvanized pipe” because it has a shiny zinc coating on its surface, which is usually silvery white or grey. This zinc coating is there to protect the steel underneath from rust and corrosion. But if you want to turn this galvanized pipe black, then we need to resort to professional painting tools.
This process involves the use of paints that are specialized for metal surfaces. However, it is important to note that once you paint it black, it means that you will lose the strong resistance to rust that the original zinc coating provides. It also means that you will need to paint it from time to time to maintain its appearance.
When deciding whether or not to change its appearance, don’t forget to consider where it will be used and what kind of environment it will encounter. If you care about corrosion protection, it is often recommended to leave galvanized piping as is, so that it retains its “silver-gray” look.
Should I use galvanized or black pipe for gas?
When it comes to choosing between galvanized or black piping for gas lines, the usual choice is black piping. Black steel pipe is the industry standard for natural gas and propane distribution systems for several reasons:
Compatibility: Black steel pipe is suitable for natural gas and propane. It does not react with these gases, which can happen when other materials are used.
Availability and Cost: Black steel pipe is readily available and is often more affordable than galvanized pipe.
Industry Standard: Black steel pipe is widely accepted as the industry standard for natural gas distribution systems used in many residential and commercial applications.
While black steel pipe is the typical choice for natural gas lines, galvanized piping may be used in some cases:
Non-Combustible Gases: Galvanized piping may be used for conveying non-combustible gases or in situations where corrosion-resistant materials are not as necessary. However, it is not recommended for combustible gases such as natural gas or propane.
OUTDOOR USE: Galvanized piping can be used for outdoor gas lines under certain circumstances. The zinc coating provides additional environmental corrosion protection.