Copper pipes are often used in plumbing systems and fixtures such as sinks, showers, faucets, and drains. They’re a popular choice thanks to their affordability and durability. But how well do copper pipes stand up against corrosion?
Copper pipes corrode over time due to exposure to high levels of dissolved oxygen, low pH, high pH, salts, corrosion-causing bacteria, and improper grounding of electrical appliances. Nevertheless, it takes a long time for copper pipes to corrode, especially with protection and regular maintenance.
If you are a home or business owner looking to install plumbing, replace old pipes, or deal with corroded metal, keep reading to learn more about copper pipes and how long they can last.
How Long Does It Take for Copper Pipes To Corrode?
Copper pipes are known for their durability and resistance to corrosion, but they’re still prone to long-term damage.
Under favorable conditions, it can take up to 20 years for copper pipes to start showing signs of corrosion.
However, this can vary depending on the environment and other variables.
Regularly inspecting and maintaining your copper pipes can help prolong their lifespan.
Additionally, you can use protective coatings like epoxy to further protect exposed copper pipes and reduce corrosion rate.
Below are the factors that affect the time it takes for copper pipes to corrode.
1. High Levels of Dissolved Oxygen
Dissolved oxygen acts as an electrolyte, allowing the oxidation reaction to occur more quickly.
It produces a thin layer of corrosion products, such as cuprite and malachite.
This layer acts as an electrolyte, allowing electricity to flow from the water to the metal surface, causing it to corrode.
When dissolved oxygen reaches concentrations higher than 5 ppm, it can lead to accelerated corrosion of copper pipes, tanks, and fixtures.
The rate of corrosion increases as the concentration of dissolved oxygen increases.
2. Low pH Levels
As water pH levels fall below 7.0, it becomes more acidic and corrosive.
Copper pipes have a relatively low tolerance for acidic conditions and are particularly susceptible to corrosion from low-pH water.
Low pH levels can cause copper pipes to corrode quickly and leach metals, minerals, and other contaminants into the water.
Corrosion of copper pipes can result in the following:
- Pinhole leaks
- Weak spots prone to bursting or cracking
- Water discoloration
Low pH levels can also contribute to the formation of deposits such as calcium carbonate and magnesium hydroxide on surfaces within the pipe system, which can further reduce the lifespan or blockages in plumbing systems.
In many cases, well water is the primary source of low pH levels in piping systems.
Well water has a naturally occurring acidity that can vary greatly depending on the system’s depth and location.
3. High pH Levels
High pH levels above 8.0 can create an imbalance of positive (Hydrogen) and negative (Hydroxide) charges on copper.
This imbalance of charges causes a reaction between copper and hydrogen, resulting in corrosion or pitting on the pipe’s surface.
Corrosion of copper pipes can lead to leaks and other plumbing problems.
To prevent corrosion, you must keep pH levels regulated, ideally between 7.0 to 7.5.
Regular water supply maintenance and testing can help avoid excessive pH levels.
Additional corrosion inhibitors or cathodic protection can reduce the corrosion rate.
Salt is an electrolyte that conducts electric current when in liquid form.
When salt water comes into contact with copper pipes, it can cause corrosion through electrolytic corrosion.
Electrolytic corrosion occurs when the electric current from the salt water causes an electric charge to build up on the metal, creating a chemical reaction that weakens the metal and causes it to corrode.
The more salt in the water, the faster corrosion will occur.
The corrosion of copper pipes can lead to pinhole leaks, pipe ruptures, and other damage that will require costly repairs or replacements.
Using a water softener can reduce the amount of salt in the water that comes into contact with copper pipes.
5. Corrosion-Causing Bacteria
Corrosion-causing bacteria can form a biofilm that adheres to the pipe walls and reduces the efficiency of the pipe.
The bacteria then create an acidic environment that corrodes the pipes and causes them to deteriorate over time.
Copper is particularly susceptible to this type of corrosion since it’s a reactive metal and reacts quickly with the environment causing the leaching of toxins into the water, which can be hazardous to human health.
Regular cleaning and monitoring for signs of deterioration help control corrosion caused by salts.
6. Improper Grounding of Electrical Appliances
Some electrical appliances produce electrical currents that can cause mineral deposits to form on the surface of copper pipes, leading to corrosion.
Household appliances such as dishwashers, washing machines, and air conditioners are all prone to causing such corrosion, as their electrical currents can cause a build-up of minerals on the inner walls of copper pipes.
In addition, installations such as water heaters, which produce a continuous flow of electricity, can also cause the corrosion of copper pipes.
Corrosion in copper pipes can reduce the life of any appliances connected to them, leading to costly repairs and replacements.
Therefore, you must ensure that all electrical installations and appliances are properly grounded to prevent corrosion.
7. Dirt and Sediment
Copper pipes can be vulnerable to hydraulic wear.
Over time, the presence of dirt and sediment in the water can cause the pipes to corrode.
As dirt and sediment accumulate inside the pipe, it can begin to erode the material of the pipe, leading to leaks, reduced flow, and eventually complete failure.
This hydraulic wear is especially damaging to copper pipes since they are soft metals with little corrosion resistance.
As the hydraulic wear continues, it can create a weakened pipe section prone to leaking and breaking easily.
Expert Richard Trethewey, from the plumbing and heating division of “This Old House”, sheds light on the reasons behind and solutions to water-pipe corrosion.
Copper is regarded as a noble metal due to its high resistance to external changes.
However, in plumbing systems, copper pipes remain prone to damage and corrosion, which can cause them to fail in less than ten years.
If you’re looking to invest in copper pipes, it’s essential to know the causes of corrosion for easier maintenance options.
Cheers, tools owners!