Steel is a very popular material due to its sturdiness and durability. Steel pipes are used to transfer air, gas and water to households as well as in industrial applications. The two most prominent selections for these purposes are black pipe and galvanized steel.

Though the usages are similar, they have some key differences which this article will provide you with all the relevant information on!

Table of Contents

What is Black Pipe?

Black pipe is made out of steel ideally to carry gas for home needs and industrial purposes too. Black pipe is typically made seamless so that it is able to prevent oil leakage. Black pipe is sturdy and so can transfer gas but at the same time, it is not conducive to water, making it prone to corrosion.

Black pipe gets its color from the formation of iron oxide during manufacturing. Black iron pipes are pretty common for transporting nautral gas to houses as well as connecting supply line in factories.

Black pipe tends to be made from low-grade steel which offers more corrosion resistance than the cast iron. Fabrication is relatively easy when compared to other materials and, the price is very reasonable which is why industries opt for this material. A well-protected environment can ensure black pipe has a life span beyond 50 years.

What is Galvanized Steel?

Galvanized pipe is a steel pipe widely used across industries to transport water. This material has improved resistance to corrosion due to the coat of zinc. Therefore, galvanized pipe can transport water seamlessly without any corrosion.

However, galvanized pipes are not used for air or gas transport because the zinc flakes may block the seamless gas passage in the long run.

Galvanized pipes are used in many various construction projects and prime usage in the irrigation process. The zinc coat on galvanized steel adds life to the pipe. Galvanized is typically more expensive than black pipe. The zinc also prevents buildup of mineral deposits that can clog the water line.

To be able to withstand the zinc coat, galvanized pipes are made from high-grade steel. Fabrication of these pipes is easy but, there are a lot of seams that must be connected. Technology to coat the pipe with zinc on longer lengths is still not proving good quality and so, it must be done in segments and welded together.

Galvanized pipes are still very popular in todays market, even when put up against all the other alternatives. Though it is more expensive than black pipe, it is less expensive than other pipes and, it adds safety to the transportation of gas.

Galvanized vs Black Pipe – Key Differences

The key differences between galvanized and black pipe are the following six factors:

  • Appearance
  • Applications
  • Corrosion Resistance
  • Cost
  • Durability
  • Manufacturing Process

Now let’s take a look at each in more detail!

Appearance

When it comes to the appearance of both, Black iron pipes are darker than galvanized pipes. The iron oxide formed during manufacturing is what results in the dark gray appearance.

On the contrary, galvanized pipes appear a silvery-white color due to their galvanization. The zinc coating results in a smoother and higher quality finish when painted.

Applications

Both pipes have distinct properties that make them ideal for certain applications. The seamless feature of black iron pipes make it the better and safer option for transporting natural and propane gas. Black pipe can also be used for fire sprinkler systems because it is more fire-resistant than galvanized pipe.

Galvanized pipes are mainly used for carrying water to supply infrastructures, while black iron pipe is liable to corrode easily from water. Galvanized pipes have the ability to resist corrosion and so are utilized for numerous outdoor and industrial applications including outdoor railings, sewage plumbing, farm irrigation and many more.

Corrosion Resistance

Their corrosion resistance is one of the key differences that separate galvanized and black pipe. Black iron pipe is manufactured using mild steel which has a low-grade carbon content. It may be necessary to further the corrosion resistance through the addition of further carbon.

Galvanized pipes are covered with a protective layer of zinc which possess and ideal property of higher corrosion resistance. This process of adding a layer of zinc is called galvanization, which also helps prevent the buildup of mineral deposits that can block the pipelines.

Cost

Black iron pipes cost less than galvanized pipes due to the absence of the zinc coating. If a budget is in mind and durability is not your primary concern, black pipes should be considered over galvanized pipes.

Durability

While it is true that steel is a very durable material, the protective zinc coating on galvanized pipes give them better strength than black pipes. This coating takes the brut of the damage rather than the steel itself, and therefore, the coating will rust before the interior. This allows the integrity of the galvanized pipe to remain intact and increase its life expectancy.

Furthermore, galvanized pipes are resistant to cracking and scratches from abrasion. Black iron pipes are uncoated and so, less durable. And, water does corrode these pipes fairly easily which reduces their durability.

Manufacturing Process

The manufacturing processes between galvanized and black iron pipe are significantly different. To manufacture galvanized pipe, a strip of iron goes through hot molten zinc. The zinc is typically heated up from 820 to 860 F. After coating, the material is cooled down in a quench tank to avoid unwanted defects.

Black iron pipes are manufactured by stretching the steel out into a seamless tube, or by forcing the edges together and sealing them with a weld.

Galvanized vs Black Pipe – Which is Best for Air, Gas and Water?

So when it comes to the transportation of air, gas and water, is galvanized or black pipe the better choice? Let’s take a look at each induvidually with the information already provided in this article.

Galvanized vs Black Pipe for Air

When it comes to transporting air, black pipe is the clear winner. Galvanized pipes are not recommended for use in air transport as the zinc coating may flake under high pressures, which will send debris through your air stream. This could potentially causes blockages as well as damaging components or any tools attached, amongst ruining the air quality itself.

Galvanized vs Black Pipe for Gas

The same applies to transporting gas as it does with air, black pipe is the far better choice. Galvanized pipes are not used for gas transport because the zinc flakes can block the gas passage.

Galvanized vs Black Pipe for Water

For transporting water, galvanized pipe is the far better material as black pipe is suspect to corrosion from water very easily. Black pipe is typically exposed to corrosion faster than galvanized pipe and so you really only have one choice when it comes to water transportation.

This youtuber below, provides a useful video on the different types of pipes used for plumbing, including galvanized and balck pipe.

FAQs (Frequently Asked Questions)

Is black pipe or galvanized pipe stronger?

Though galvanized pipe is more durable than black pipe due to its protective coating of zinc, black pipe is typically stronger because it is manufactured without a seam.

What is the difference between black pipe and galvanized?

Galvanized pipe has a zinc coating on the surface which boosts corrosion resistance and is suitable for transporting water. Black pipe is uncoated and suited to transporting gas but corrodes when in contact with water. Galvanized pipe is not suitable for transporting gas however, as the zinc coat may flake off.

What is cheaper galvanized or black pipe?

Black pipe is typically cheaper than galvanized pipe due to the protective coating on galvanized pipe which adds to the costs and the manufacturing process in which it undergoes. Galvanized fittings are also more costly than those used on black pipe due to their maintenance demands.

Why is galvanized pipe bad?

Over time, galvanized pipes will corrode and rust. This rust will accumulate inside the pipes and make the passage smaller and smaller, compromising water flow.

Useful Reading


If you have any questions regarding galvanized vs black pipe for air, gas and water, please leave a comment below, with a photo if applicable, so that someone can help you!