Corrosion coupons are one of the simplest and lowest cost tools used to determine average corrosion rates in a cooling water system. Corrosion coupons are small bars of metal or alloys that are pre-weighed and measured that are inserted into a system for a predetermined period of time, usually 30, 60, 90, or even 120 days. After this time, the coupons are removed from the system and returned to the supplier for analysis. An average corrosion rate is calculated by determining the average weight loss of the coupons.
These coupons are placed in the system by way of a coupon rack. A coupon rack is a specific piping arrangement that holds the coupons securely in place and maintains a constant flow past the coupons.
The Lakewood Instruments model 9050 Cooling Tower Corrosion Coupon Rack, also known as a corrosion coupon holder, is a 4-coupon system made from ¾” PVC. It includes shut-off valves and a 5gpm flow regulator. It is rated at 140 psi at 100F, with a maximum temperature of 140F. The four coupon holders allow for the evaluation of the corrosion rate of multiple metals at a time reflecting the composition of the system as a whole.
Corrosion coupons have the benefit of:
- Low cost
- Easy to use
- Provides information to evaluate the effectiveness of your chemical treatment program
- Can be used for specific types of corrosion
- Do not require the use of complicated instrumentation
- Identifying corrosion rate trends
- 1167416 – Corrosion Coupon Rack for four coupons
- 1167500 – Coupon Holder