Technical Update: Using Corrosion Coupons

Adam Griffith’s May 2023 Technical Update

What are Corrosion Coupons?

These coupons are small metal samples that are placed in a water system to evaluate corrosion rates. The coupons are made of the same metal as the equipment being monitored and are installed in a representative location within the system. The coupons are then removed at regular intervals and analysed to determine the extent of corrosion that has occurred.

Uses of Corrosion Coupons

These types of coupons are used for a variety of reasons, including:

• Monitoring corrosion rates over time
• Determining the effectiveness of corrosion inhibitors
• Evaluating the impact of changes in water chemistry on corrosion rates
• Comparing corrosion rates between different systems or equipment
• To assess the need for maintenance or repair of equipment

How do Corrosion Coupons Work?

When installed in a water system, the coupons are exposed to the same water chemistry and conditions as the equipment being monitored. Over time, the metal of the coupon will corrode at a rate proportional to the corrosion rate of the equipment. The coupons are removed at regular intervals and analysed to determine the extent of corrosion that has occurred. This analysis typically involves measuring the weight loss and examining the surface of the coupon for signs of corrosion.

It is important to note that the results obtained from these coupons are only representative of the specific location where the coupons were installed. Other areas of the equipment may experience different corrosion rates due to variations in water chemistry or other factors.

Conclusion

They are an effective tool for monitoring and evaluating corrosion rates in water systems. By regularly analysing the coupons, equipment owners can assess the effectiveness of corrosion inhibitors, evaluate the impact of changes in water chemistry, and determine the need for maintenance or repair. However, it is important to keep in mind that the results obtained from coupons are only representative of the specific location where the coupons were installed.

At Hydro-X Water, we recognise the significance of efficient system upkeep to reduce maintenance and repair expenses. With more than three decades of experience in the industry, we possess extensive knowledge of water system corrosion and employ tools, such as this one, to observe and assess alterations within your systems.

Contact our team today to assess the effectiveness of your site’s system today and explore implementing our corrosion coupons in your water systems which are available on request.