‘Erosion Corrosion’ in Water Systems

What is ‘Erosion Corrosion’ in Water Systems? 

What Causes ‘Erosion Corrosion’?

The design of the water system plays a significant role.

The two main points are described below:

1. Water velocity:

High velocities, especially for prolonged periods, can cause metal surface erosion, leading to corrosion.

2. Temperature:

High temperatures also increase the risk of erosion corrosion.

The risk is notably higher in hot water systems (~60°C/140°F) than in cold water systems. 

Because of the prolonged periods of flow, and high temperatures, hot water recirculation systems are at a high risk for erosion corrosion,

Pro tip: Try using our free pipe velocity calculator to calculate the velocity of your water system and learn about recommended system velocities.

What are the Consequences of ‘Erosion Corrosion’?

Erosion-corrosion in a water system can have several negative consequences, including:

• Reduced system efficiency:
  • Damaged pipes lead to reduced system performance.
• Leaks:
  • Erosion-corrosion can weaken a pipe’s structural integrity, leading to failure and building damage.
• Reduced safety:
  • Erosion-corrosion can cause the failure of critical pipes, such as in a hospital.
• Environmental impacts:
  • There can be a significant amount of water wasted.

How do you prevent ‘Erosion Corrosion’?

As an engineer designing a water system, the two main tasks you must undertake to avoid erosion corrosion are:

1. Accurate Calculations:

To design your system correctly, you must:

• Calculate the peak flow rate/recirculation flow rate going through the pipe.
  • If the flow rate is underestimated, the real-life velocity will be higher than your calculation.
• Choose a suitable pipe size where the velocity is below the maximum threshold.
  • If the pipe is undersized, the real-life velocity will be higher than your calculation.
• Balance the hot water system pressures to ensure the recirculation flow rate goes through each circuit as intended.
  • If the system is not balanced, the real-life flow rates and velocity will be higher than your calculation.

2. Correct Equipment:

Mains water Pipe size calculator allow for accurate calculations, you must choose the correct equipment to ensure the system operates correctly.

• The recirculation pump duty must accurately match the system duty to ensure the flow rate (and therefore the velocity) does not increase. 
• The balancing valves must be tuned and commissioned correctly to ensure the recirculation flow rate goes through each circuit as intended.

Suggested reading: To learn about designing, calculating, and choosing the correct hot water recirculation pump, check out this article.

Materials Susceptible to ‘Erosion Corrosion’

Copper Pipes

Copper pipes are susceptible to erosion corrosion, requiring low water velocities.

Stainless Steel Pipes

Stainless steel pipes are known for their higher resistance to erosion corrosion. However, at high velocities, it will still occur.

Plastic Pipes

Plastic pipes also have a higher resistance to erosion corrosion. However, at high velocities, it will still occur.

h2x is a plumbing system design software built to ensure compliance, efficiency, accuracy and collaboration. 

The automated calculations for flow rates, velocities, recirculation pump duties, and balancing valves mean that you won’t need to worry about erosion corrosion on your projects.

h2x’s straightforward user interface helps engineers produce high-quality designs and work more efficiently, all while adhering to industry regulations.

The software has already been used to size millions of kilometres of pipes in projects across the world.

Book a demo with us today to discover how H2X can help you improve your design and calculation workflow.