Unravel the mystery: why pex fittings corroded in your home (you need to know this!)
What To Know
- Oxygen is a natural element that can cause corrosion in PEX fittings.
- When oxygen is dissolved in water, it can react with the metal to form oxides, which can weaken the fitting.
- To prevent galvanic corrosion, use PEX fittings that are compatible with the other metals in the plumbing system.
PEX (cross-linked polyethylene) fittings are widely used in plumbing systems due to their flexibility, durability, and resistance to corrosion. However, under certain conditions, these fittings can experience corrosion, leading to leaks and system failures. Understanding the causes of PEX fitting corrosion is crucial for preventing these issues and maintaining the integrity of plumbing systems.
Types of Corrosion
Corrosion in PEX fittings can manifest in two primary forms:
- Electrochemical Corrosion: Occurs when two dissimilar metals are in contact with each other in the presence of an electrolyte, such as water. The more active metal will corrode, while the more noble metal will be protected.
- Chemical Corrosion: Occurs when PEX fittings are exposed to corrosive chemicals, such as chlorine, bleach, or acidic cleaners. These chemicals can attack the protective layer on the fitting, leading to corrosion.
Causes of PEX Fitting Corrosion
1. Galvanic Corrosion
Galvanic corrosion is the most common cause of PEX fitting corrosion. It occurs when PEX fittings are connected to dissimilar metals, such as copper or brass. The more active metal, usually zinc, will corrode, sacrificing itself to protect the more noble metal.
2. Chlorinated Water
Chlorine is added to municipal water supplies to kill bacteria. However, high levels of chlorine can corrode PEX fittings over time. Chlorine breaks down the protective layer on the fitting, exposing the underlying metal to corrosion.
3. Bleach
Bleach is a powerful oxidizing agent that can quickly corrode PEX fittings. It is often used for cleaning and disinfecting plumbing systems, but it should not be applied directly to PEX fittings.
4. Acidic Cleaners
Acidic cleaners, such as vinegar or muriatic acid, can also corrode PEX fittings. These cleaners should not be used on PEX systems.
5. Oxygen
Oxygen is a natural element that can cause corrosion in PEX fittings. When oxygen is dissolved in water, it can react with the metal to form oxides, which can weaken the fitting.
6. High Temperatures
High temperatures can accelerate corrosion in PEX fittings. PEX fittings are rated for specific temperature ranges, and exceeding these ranges can lead to corrosion.
Preventing PEX Fitting Corrosion
1. Use Compatible Metals
To prevent galvanic corrosion, use PEX fittings that are compatible with the other metals in the plumbing system. For example, use brass fittings with copper pipes and PEX fittings with PEX pipes.
2. Control Chlorine Levels
If possible, reduce the chlorine levels in your water supply. You can do this by installing a water filter or using a chlorine-neutralizing agent.
3. Avoid Bleach
Never apply bleach directly to PEX fittings. If you need to clean or disinfect your plumbing system, use a bleach-free cleaner.
4. Use Non-Acidic Cleaners
Avoid using acidic cleaners on PEX systems. Instead, use non-acidic cleaners specifically designed for PEX.
5. Protect from Oxygen
To prevent oxygen corrosion, use oxygen barriers in your plumbing system. These barriers can be installed at the water heater or on individual fixtures.
6. Maintain Proper Temperatures
Operate your plumbing system within the recommended temperature ranges for PEX fittings. Avoid exposing PEX fittings to extreme temperatures.
Signs of PEX Fitting Corrosion
- Leaks
- Discoloration
- Pitting
- Flaking
- Reduced water pressure
Troubleshooting Corroded PEX Fittings
If you suspect that your PEX fittings are corroded, take the following steps:
- Identify the source of the corrosion: Determine the type of corrosion and its cause.
- Replace corroded fittings: Remove and replace any corroded fittings with new, compatible fittings.
- Address the underlying cause: If the corrosion is caused by galvanic corrosion, install a dielectric union to isolate the dissimilar metals. If the corrosion is caused by chlorine or bleach, reduce the exposure to these chemicals.
The Bottom Line: Safeguarding Your Plumbing System from PEX Fitting Corrosion
Understanding the causes of PEX fitting corrosion is essential for preventing these issues and ensuring the longevity of your plumbing system. By following the recommended preventive measures, you can safeguard your PEX fittings from corrosion and maintain a safe and reliable water supply.
Quick Answers to Your FAQs
Q: Can I repair corroded PEX fittings?
A: No, it is not recommended to repair corroded PEX fittings. Once a fitting has corroded, it is weakened and should be replaced.
Q: How often should I inspect PEX fittings for corrosion?
A: Inspect PEX fittings regularly, especially in areas where they are exposed to corrosive chemicals or high temperatures.
Q: Is it safe to use PEX fittings in hot water applications?
A: Yes, PEX fittings are rated for use in hot water applications. However, it is important to use fittings that are compatible with the temperatures of your hot water system.
Q: Can I use PEX fittings with copper pipes?
A: Yes, but it is important to use a dielectric union to prevent galvanic corrosion.
Q: What is the best way to clean PEX fittings?
A: Use a non-abrasive cleaner specifically designed for PEX. Avoid using acidic cleaners or bleach.
