Ductile Iron Pipe vs Galvanized Steel Pipe

There are many types of materials to use for pipes for various applications. Two popular types of pipes are Ductile Iron Pipes and galvanized steel pipes. Both of these types have advantages and specific applications. However, there are a few key differences between ductile iron and galvanized steel pipes. Durability, corrosion resistance, strength, flexibility, and maintenance are the most crucial differences between these two types of piping. There are some technical specifications to consider when choosing a more suitable option for your project needs. Comparing these technical features will help you choose the most suitable option based on your specific needs and priorities.

What Are Ductile Iron Pipes?

Ductile iron is cast iron with an enhanced level of strength, durability, and reliability. Ductile iron pipes are a sort of ductile iron that is used in various applications, such as high-pressure environments. These pipes are mainly used in water and wastewater systems. Due to the many benefits of ductile iron pipes, they have other industrial applications that make them a popular and practical choice.

Advantages of Using Ductile Iron

Easy Installation: Ductile iron pipes have proven to be easy to install. These pipes can be installed with a variety of joints. The easy installation process of ductile iron pipes is why they are widely used to fit various applications.
Strength and Durability: Ductile iron has an improved level of strength. Pipes that are made of ductile iron are commonly long-lasting and have the ability to withstand high pressure.
Cost-effective: Ductile iron pipes generally offer the required performance with much lower initial costs. Other types of piping, such as copper or steel, will do the job with higher expenses.
Corrosion Resistance: Due to some microstructural features, ductile iron pipes show good corrosion resistance. This helps them maintain a desirable performance for a long time.

Common Applications for Ductile Iron

Gas Distribution: Ductile iron pipes are widely used in gas distribution networks. This is because of their high strength in such conditions. Also, being resistant to corrosion is a key factor for this application.
Industrial Applications: Ductile iron pipes are widely used in industrial settings. Their strength in high-pressure environments allows them to transport fluids.
Water and Sewage Systems: When it comes to water and wastewater systems, the main critical feature the piping must have is corrosion resistance. Ductile iron pipes are fairly resistant to corrosion and have a high level of durability and strength.
Fire Protection Systems: Ductile iron pipes are very popular for fire protection systems. They are reliable, durable, and strong. More importantly, they offer excellent strength and resistance to high temperatures.

What Are Galvanized Steel Pipes?

According to Difference Between, galvanized steel pipes are, in fact, a type of steel pipe that is coated with a thin layer of zinc. This protective external layer helps the pipe resist corrosion. The mechanism is that the zinc layer corrodes before anything happens to the steel layer. This gives the pipe a much longer service life, even in corrosive environments. Galvanized steel pipes provide a strong, durable, cost-effective, and corrosion-resistant piping system. There are many galvanized steel pipe uses because they are widely available.

Advantages of Using Galvanized Steel

Wide Availability: Galvanized steel pipes can be easily supplied. They are widely available due to the versatility of their materials.
Strength and Durability: These pipes provide a good and acceptable amount of strength and durability, which makes them perfect for various applications.
Corrosion Resistance: Galvanized steel pipes offer perfect corrosion resistance due to their zinc coating. This layer provides good protection against rust and corrosion.
Cost-effective: These pipes are generally cost-effective mainly because of their versatility. They are typically less expensive, especially compared to some other types of pipes, such as stainless steel pipes.

Common Applications for Galvanized Steel

Construction: These pipes are commonly used in construction projects. They are applied as structural support, scaffolding, or other construction applications.
Water Distribution Systems: Galvanized steel pipes are widely used in water distribution systems. Their high corrosion resistance helps the water maintain its quality.
Fencing and Railing: These pipes are suitable for fencing and railing applications because they offer high strength, durability, and corrosion resistance.

What Are the Key Differences Between Ductile Iron and Galvanized Steel Pipes?

There are some key differences between ductile iron pipe and galvanized steel pipe. However, some of these differences are not very significant. Both types of pipes have advantages and disadvantages. The application of the pipes will determine which type to choose.

Durability

Ductile Iron: They have proven to have a long lifespan, excellent reliability, and durability. They are especially useful for applications in harsh environments and can withstand high pressure.
Galvanized Steel: Galvanized steel pipes, too, offer acceptable durability. However, the zinc coating typically wears off after a while; thus, the durability of the pipes can be threatened.

Corrosion resistance

Ductile Iron: Ductile iron pipes are highly resistant to corrosion. A simple protective coating applied to the pipes’ surface can enhance this resistance.
Galvanized Steel: These pipes already have a protective zinc coating, which gives them excellent resistance to corrosion. However, after the zinc coating wears off, the steel underneath is highly prone to corrosion.

Strength

Ductile Iron: Referring to The Piping Mart, ductile iron pipes can tolerate high pressures or heavy loads, making them a good choice for several industrial applications.
Galvanized Steel: These pipes will provide a conventional amount of strength; however, their strength generally depends on the thickness of the steel that is used.

Flexibility

Ductile iron: They can be flexible, especially when bearing ground movements. This flexibility comes in handy when the pipes resist cracking or breaking under stress.
Galvanized Steel: The difference in flexibility between ductile iron pipe and galvanized steel pipe can be significant. This type of pipe is somehow less flexible, which makes it a less suitable choice for environments likely to face ground movements.

Maintenance

Ductile Iron: Ductile iron pipes require less maintenance in a normal application. Their corrosion resistance will prevent leaks. However, regular inspection can be useful to extend their lifespan.
Galvanized Steel: These pipes usually require more maintenance. Since the protective zinc layer wears off, regular inspections or even replacement of pipes would be necessary in this type of piping.

Which Type of Pipe Should You Choose, Ductile Iron or Galvanized Steel?

The differences between ductile iron pipe and galvanized steel pipe determine the type of piping you have to choose for your projects. Several factors, such as the specific application, environment, and project requirements, must be considered to end up making the wisest decision. Also, the key features of these pipes are critical to pay attention to: features such as strength and pressure requirement, availability, costs, and corrosion resistance. The final decision mainly depends on your priorities and specific needs.

The table below compares the technical specifications of ductile iron pipe and galvanized steel pipe.

Property	Ductile Iron Pipe	Galvanized Steel Pipe
Material	Iron and carbon	Steel coated with zinc
Strength	High	High
Durability	High	Good
Corrosion resistance	Excellent	Good
Pressure resistance	High	Moderate to high
Ease of installation	Moderate	Easy
Flow characteristics	Smooth	Smooth to rough
Wall thickness	Thicker	Thinner
Cost	Moderate	Low to moderate
Maintenance requirements	Low	Moderate

Conclusion

Based on your project needs, both of these types of pipes can be the better option. First, you should come up with a list of priorities regarding technical specifications and performance of the piping. Each of these types can give your project the necessary requirements. However, ductile iron pipes usually provide a good balance between all the required features and specifications for most project needs.