Acero galvanizado vs. cobre: comparación y elección de tuberías

Galvanized steel and copper are both popular materials for piping systems. While galvanized steel has a protective zinc layer, its corrosion resistance is generally lower than that of copper pipes. On the other hand, copper pipes are more costly than galvanized ones.

Choosing the right material for a piping system depends on the specific application and the properties of each material. In this article, we’ll explore the key differences between galvanized and copper pipes, and discuss their ideal applications to help you build the best piping system for your needs.

Chemical Differences Between Galvanized and Copper Pipes

Composición

Galvanized pipes are made from steel that is coated with a layer of zinc. The steel provides strength and the Z coating adds protection.

Copper pipes can be made from pure copper or copper alloys. Pure copper pipes are common for plumbing, but copper alloys, which include small amounts of other metals like zinc or tin, are also used to improve certain properties.

Resistencia a la corrosión

Copper pipes are more resistant to corrosion than galvanized pipes. Copper naturally resists corrosion and does not need any protective coating. In contrast, galvanized pipes have a zinc layer that protects the steel beneath. Over time, this zinc coating can wear away, exposing the steel beneath to the risk of rusting.

Corrosión galvánica

Galvanized pipes are more prone to galvanic corrosion when connected to copper pipes, while copper pipes are less affected by this issue. This difference occurs because zinc, which coats galvanized pipes, is more reactive than copper in the galvanic series of metals. 

When galvanized steel and copper are in contact with the presence of an electrolyte like water, the zinc layer on the galvanized pipe acts as the anode and corrodes faster. This accelerates the deterioration of the galvanized pipe, whereas the copper pipe remains largely unaffected due to its lower reactivity.

Oxidación

Copper pipes are less susceptible to oxidation than galvanized pipes. Copper can naturally form a thin oxide layer that protects it from corrosion. 

Galvanized pipes rely on a zinc coating to safeguard the steel underneath from rust. Over time, this zinc layer can wear off, exposing the steel to oxygen and moisture, which leads to rust. 

Physical Differences Between Galvanized and Copper Pipes

Fuerza

Galvanized pipes are stronger and more resistant to impact than copper pipes. This is because galvanized pipes have a steel core, which gives them higher strength for tough conditions. Copper pipes, while durable, are softer and more flexible, making them less able to handle physical stress. In situations where extra strength is needed, galvanized pipes are the better choice.

Heat Conductivity

Copper pipes have much higher heat conductivity than galvanized pipes. This means copper pipes transfer heat more efficiently. The reason is that copper is an excellent conductor of heat, while galvanized pipes are made of steel coated with zinc, both of which have lower thermal conductivity. 

Durabilidad

Copper pipes are more durable than galvanized pipes. Copper does not need a protective coating and can maintain its integrity for decades. However, galvanized pipes are stronger and more resistant to physical damage, making them a good choice in tough conditions. 

Conductividad eléctrica

Copper pipes conduct electricity much better than galvanized pipes, making them ideal for applications where electrical grounding is needed. On the other hand, galvanized pipes are safer in situations where you want to avoid electrical currents, as their lower conductivity reduces the risk of accidental shocks.

Other Differences Between Galvanized and Copper Pipes

Installation

Galvanized pipes are more difficult to install. At high temperatures, the zinc layer can break down, releasing toxic fumes and affecting the weld quality. Galvanized pipes are typically connected using threaded joints or mechanical fittings rather than welding. This makes installation more time-consuming and labor-intensive.

Copper pipes can be joined through soldering, which is generally quicker and simpler. This ease of installation makes copper a more convenient choice, especially for residential and small-scale applications.

Coste

Galvanized pipes generally cost less than copper pipes. However, the initial cost savings may be offset by the need for earlier replacement. Copper pipes, while more expensive upfront, tend to have fewer long-term maintenance costs.

Health and Safety

For residential water transport, copper pipes are safer than galvanized pipes. Copper’s natural antibacterial properties help keep the water clean, promoting better water quality. 

Older galvanized pipes, however, may contain lead, which is harmful to human health. Additionally, the corrosion of the zinc layer in galvanized pipes can sometimes impact water quality.

How to Choose Galvanized or Copper Pipes in Some Common Applications？

Galvanized and copper pipes share several common applications. To select the most suitable pipe, it’s essential to consider the specific requirements of each case.

If strength and moderate corrosion resistance are needed, galvanized pipes offer a cost-effective and durable choice. However, if higher corrosion resistance and safety are priorities, copper pipes are the better option.

• Residential Water Supply Systems

Copper pipes are preferred for residential water supply because they offer better corrosion resistance and are lead-free, making them safer for drinking water. Galvanized pipes were once commonly used in home water systems but have gradually been replaced by copper and other safer materials.

• Sistemas HVAC

Copper pipes are widely used in heating and cooling applications due to their excellent thermal conductivity. Galvanized pipes are typically used for structural support or in external cooling water lines that require higher strength and durability.

• LPG Piping

Copper pipes are more common in small residential gas supply systems because they are easy to install and have good corrosion resistance. For larger commercial and industrial gas systems, galvanized pipes are often preferred for their impact resistance and structural stability.

• Fire Sprinkler Systems

In large-scale fire sprinkler systems, galvanized pipes are the preferred choice due to their high-pressure tolerance and durability. For smaller residential and office sprinkler setups, copper pipes are commonly used because they are easier to install in compact spaces.

Different Applications of Galvanized and Copper Pipes

Below are the distinct application areas where galvanized and copper pipes serve entirely different purposes. 

Galvanized Pipes

• Outdoor Fencing and Structural Framework
• Electrical Conduit in Industrial Settings
• Underground Water Lines in Irrigation Systems
• Heavy-Duty Construction Support

Copper Pipes

• Medical Gas Systems in Healthcare Facilities
• High-Efficiency Solar Water Heating Systems
• Refrigeration and Air Conditioning Systems
• Distillation and Brewing Equipment

How to Identify Galvanized Pipe or Copper Pipe？

When trying to identify whether you are dealing with a galvanized pipe or a copper pipe, several key features can help you make the distinction. Here are the most effective methods:

Color

Galvanized pipe has a gray or silver appearance because of its zinc coating. Over time, it may develop a duller, sometimes rusted look.

Copper pipe is usually a distinctive reddish-brown or gold color. As it ages, it may develop a greenish patina, especially if exposed to moisture.

Prueba de imán

Galvanized pipes are made of steel, so they are magnetic. If a magnet can stick to the pipe, it is probably made of galvanized steel.

Copper pipes are non-magnetic. If the magnet does not stick, the pipe is probably made of copper.

Age and Usage

Galvanized pipes were usually used in homes built before the 1960s. If you’re inspecting older plumbing, especially in older buildings, you’re more likely to encounter galvanized pipes.

Copper pipes have been widely used since the 1960s, so newer constructions or plumbing renovations are more likely to have copper piping.

Sound Test

Galvanized pipes tend to produce a duller sound when tapped due to the zinc coating and steel core.

Copper pipes emit a clearer, metallic sound when struck lightly.

Trusted Partner in Galvanized Steel

Grupo Steel Pro offers a wide range of galvanized steel products, ensuring they meet industry standards for quality and durability. We pride ourselves on timely deliveries, so you can count on us for your project needs. To get a quote tailored to your requirements, please haga clic aquí.