Definition - What does Corrosion Coupon mean?
A corrosion coupon is a simple and very effective tool that gives a quantitative estimate of corrosion rates that take place within a specific operating system. These coupons also offer a visual signal of the corrosion type that may be occurring in the system under observation.
This tool can greatly help in precise corrosion rate monitoring in any critical environment. It is beneficial in terms of:
- Repair costs
- Measurement of material failure
Corrosion coupons are also known as corrosion monitoring coupons.
Corrosionpedia explains Corrosion Coupon
Corrosion coupons provide a cost-effective means of monitoring that allows corrosivity measurement in a system in the most accurate manner. This is usually done through the observation of the corrosion rate in mils per year of a coupon exposed in the system. With this, valuable data can be extracted about the life expectancy of materials.
Coupons are pieces of metal that are available in varying shapes, sizes and materials. They are composed of the same chemical composition as the equipment to be monitored. Corrosion coupons are exposed to a corrosive solution similar to that in process facilities for a specified period of time, and can give visual signs of the corrosion rate and type.
Such coupons are usually stenciled with a unique serial number for easy identification.
The three most common types of coupons are:
- Strip ¾ - This is the most widely used coupon for all corrosion evaluations.
- Strip ½ - This is widely used with narrow ports or low-pressure equipment.
- Disc - This coupon type is applied in multiple or stacked monitoring applications.
With the aid of these erosion and corrosion monitoring coupons, studies are successfully conducted to meet the highest level of standards.