Which Pipe Is Best for Gas: Galvanized or Black Steel?

Choosing the right material for gas pipes is important for safety, durability, and compliance. The two most commonly used gas pipes are galvanized steel pipes and black steel pipes. Although they are both made of carbon steel, they have different performance and uses due to different surface treatments.This article will show you the difference between black steel pipes and galvanized steel pipes, which one is more suitable for use in gas systems, and what precautions should be taken when installing in homes or commercial places to make gas pipes safer and more reliable.

Why Galvanized Pipe Should Not Be Used for Gas Lines？

Advantages of Using Black Steel Pipe for Gas Systems

Can You Mix Galvanized and Black Steel Pipe?

In some older buildings, you may find a combination of galvanized and black steel pipes. While this may not always be a code violation, mixing these two metals is generally not recommended due to the potential for galvanic corrosion. When different metals are connected, they can react with each other, especially in the presence of moisture, accelerating rust and reducing the pipe’s lifespan.

If mixing is unavoidable, a dielectric union should be used to separate the metals and prevent corrosion. However, it’s always best to check with your local building inspector or plumbing authority before combining materials.

What Is the Difference Between Galvanized and Black Steel?

Galvanized and black steel are both types of carbon steel, but they differ in their coatings and uses:

Galvanized Steel: Coated with a layer of zinc to protect against corrosion, primarily used in water pipes and outdoor structures.
Black Steel: Has no coating, giving it a black appearance, and is typically used for gas and fire sprinkler systems.

While galvanized steel is good for water systems, it’s not ideal for gas due to the potential for the zinc coating to deteriorate and affect the flow of gas. Black steel, on the other hand, is the preferred material for gas lines due to its strength and reliability.

Which Type of Pipe Cannot Be Used for Gas?

Certain types of pipes should not be used for gas installations due to safety and performance concerns. These include:
PVC Pipes: Not suitable for gas systems as they can easily crack under pressure and may emit harmful fumes when exposed to heat.
Copper Pipes: Copper can corrode over time when exposed to gas, particularly with natural gas, and can weaken the pipe.
Galvanized Steel: As mentioned, the zinc coating can flake off and cause blockages or leaks in the gas line.
It’s essential to select materials that are designed specifically for gas lines, such as black steel or certain flexible stainless steel tubing.

Best Pipe for Natural Gas

The best pipe for natural gas is typically black steel. Black steel pipes are strong, durable, and resistant to the corrosion issues that galvanized pipes face. They are capable of handling the pressures and conditions that come with natural gas distribution. For underground installations, ensure that the pipes are coated or shielded from corrosion.

In some cases, flexible stainless steel tubing (CSST) can also be used for natural gas lines. This type of pipe is flexible, easy to install, and can be a great option for both residential and commercial gas systems. However, it should be installed by a certified professional to ensure compliance with safety regulations.