Stainless steel and copper are two popular materials used in piping systems. Pipes made of these materials stand out in their performance and durability. However, these two piping materials differ significantly. Those distinctions lead people to debate stainless steel pipes vs copper pipes.
You’ll see people favoring stainless steel pipes for their superior performance and durability. However, copper pipes have been used for centuries, but they are weaker and require higher maintenance costs. In this article, I will compare stainless and copper pipes head-to-head. This will help you choose the right type of pipes for your custom needs.
Differences Between Stainless Steel and Copper Pipes
The significant differences between these two pipes lie in their composition. The stainless steel pipes contain higher chromium content, making them a superior option. On the other hand, copper pipes are made of either pure copper or copper alloys. Remember, because copper is a soft material, it makes the pipes less hard and less strong. Let’s jump in and discuss their differences in detail.
1- Material Composition
As I said earlier, the composition of these two materials imparts different properties to the pipe they make. Stainless steel is an alloy composed of various alloying elements. Those include iron, chromium, molybdenum, manganese, and a few others. However, stainless steel contains over 10.5% chromium, which makes it unique.
This chromium reacts with oxygen, forming an oxide layer on the surface of the stainless pipe. The presence of this layer makes these pipes more durable. On the other hand, copper pipes are made of pure copper or its alloy. Remember, copper is a softer material, so pipes made of it are softer and less hard. These pipes also offer decent corrosion resistance.
2- Strength & Weight
Stainless steel pipes are stronger than copper pipes. Why? The reason is that stainless steel has a tensile strength of around 500–800 MPa. On the other hand, copper is very weak, having a tensile strength of below 250 MPa. As a result, the stainless pipe can withstand high strength, pulling, or other stresses.
However, copper pipes can break if subjected to stretching or pulling forces. The higher tensile strength of stainless pipes comes at a trade-off: they are heavier. As a result, these pipes are a bit more challenging to carry and install. The copper pipes are lightweight and easy to carry. Additionally, lower tensile strength makes their cutting and threading easier during installation.
3- Corrosion Resistance
Both copper and stainless pipes are generally corrosion-resistant. However, I consider stainless pipes to be slightly superior in terms of corrosion resistance. The reason is that stainless materials have chromium, which forms a chromium oxide layer when it reacts with oxygen. This oxide layer protects the stainless pipe’s surface from corrosion.
Remember, this layer can heal itself if it undergoes scratches or even depletion. On the other hand, copper offers excellent resistance to corrosion. Copper also forms a greenish layer when it reacts with oxygen. This layer, known as patina, can protect the pipes from corrosion and other factors.
However, this patina layer is sensitive and can be damaged in acidic conditions. So, these pipes can corrode when they handle water with a higher acidic nature. The stainless pipes won’t face any issue, no matter how low the pH of the water is. As a result, stainless steel pipes are used in plumbing systems that handle water with low pH.
4- Pressure Rating or Handling
Stainless pipes are suitable for pipelines that handle higher-pressure fluids. Why? That’s because stainless steel material has higher tensile strength. So, it can withstand extreme pressure with ease and doesn’t deteriorate. On the other hand, copper pipes have less tensile strength. So, they are weaker, softer, and cannot withstand higher pressure.
You won’t see copper pipes in oil or gas transmission. Most stainless pipes have pressure ratings of around 1500 psi. On the flip side, the copper pipes have ratings less than 500 PSI, which is very low. I consider copper suitable only for domestic water pipelines and stainless steel for industrial use.
5- Maintenance & Overall Lifespan
Both stainless steel and copper pipes are excellent for durability. However, the copper pipes are an inferior option in terms of maintenance costs. Stainless steel offers better corrosion resistance in water with low pH. The average lifespan of stainless pipes is around 55 to 65 years. These pipes require little to no maintenance due to their better strength.
On the other hand, copper pipes are somewhat compromised and can last 40 to 50 years. But the major problem is their regular maintenance cost. As I said earlier, copper pipes are weaker, prone to deterioration, and require regular checks. Remember, if you leave them without maintenance, these pipes can deteriorate quickly.
Quick Highlight: The lifespan of copper pipes can be reduced even further if they handle water with low pH levels. Remember, water with a lower pH becomes more acidic, which can affect the internal surfaces of these copper pipes. If copper pipes handle such water, that’s fine. However, prolonged exposure to acidic water can significantly shorten the lifespan of these pipes.
6- Ease of Installation & Temperature Resistance
Copper pipes are much easier to install than stainless steel pipes. The reason is that copper is a soft material. Its cutting, welding, soldering, and threading can be easily done. You won’t need high-end machines for their cutting during installation. On the other hand, stainless steel is stronger but harder, and it is less friendly to welding.
Additionally, its cutting and threading are also challenging and time-consuming. This makes the stainless steel more challenging to install. Regarding temperature resistance, stainless steel material is a superior option. These stainless steel pipes can withstand temperatures of around 800 degrees Celsius. However, copper pipes can withstand temperatures below 350 degrees Celsius. Temperatures in this range will cause deterioration of the copper pipes.
7- Heat Retention & Thermal Conductivity
Have you ever noticed that copper pipes or tubes are used in refrigeration systems? That’s because of their higher thermal conductivity or lower heat retention. Remember, copper conducts heat quickly, so do the pipes made from it. The copper pipes cannot retain heat; they transfer it.
On the other hand, stainless steel pipes have low thermal conductivity and higher heat retention. It means they retain heat and tend to transfer it very slowly. You’ll see these stainless pipes in hot water transport or steam systems. Stainless steel pipes retain heat, keeping the water at a stable temperature.
8- Cost & Use Cases
The price of stainless steel is higher, which is a big drawback. But I still favor it due to its low ongoing cost. Remember, stainless steel pipes don’t require regular maintenance, which can increase ongoing costs. Additionally, copper material is relatively inexpensive compared to stainless steel. But the copper pipes require maintenance, which is a drawback.
You pay less at first with copper pipes, but keep spending on their maintenance. Stainless steel is suitable for high-pressure applications. However, the copper pipes are a bit weaker and fragile. As a result, they are only appropriate for low-pressure applications. Here is the table showing the application of both of these pipes:
| Stainless Steel Pipe Applications | Copper Pipe Applications |
| Chemical processing plants | Residential water supply systems |
| Marine and coastal environments | Heating, ventilation, and air conditioning (HVAC) |
| Food and beverage production lines | Refrigeration and cooling systems |
| High-pressure steam and gas systems | Medical gas and oxygen lines |
| Oil, gas, and petrochemical pipelines | Gas distribution in buildings |
| Architectural structures and handrails | Solar water heating systems |
Frequently Asked Questions
Is copper or stainless steel pipe better?
Stainless steel pipes are a better option than copper pipes. The reason is that these stainless pipes last longer and withstand high pressure. Additionally, they perform better in chemical transport.
Why don’t plumbers use copper pipes?
Nowadays, plumbers don’t prefer copper pipes because they’re less durable. Copper material reacts with impurities or minerals of the water and can deteriorate quickly. The wear-out rate of copper pipes is higher than that of stainless steel pipes. As a result, plumbers prefer stainless steel pipes over copper.
Are copper pipes bad for water?
No, copper pipes can perform better when used for transporting water. However, if this water has a lower pH (acidic), then these pipes can wear out quickly. As a result, modern plumbing relies heavily on stainless steel pipes.
Verdict: Which One Should You Choose, Stainless Steel or Copper Pipes?
I favour stainless steel pipes 10 out of 10 times. Reason? That’s because these pipes deliver better performance even under high-pressure conditions. These pipes can last longer and require no regular maintenance. You can use them in almost every industry and application. However, if you have a tight budget, stainless steel pipes may not be the best choice.
In such a case, I recommend going for copper pipes. Remember, these pipes have a shorter lifespan and can deteriorate quickly, especially when handling water with low pH. If you choose copper pipes, you’ll have to bear some drawbacks. One of the most significant disadvantages of these pipes is the need for regular maintenance. You analyze your specific use case and then choose between stainless and copper pipes.