One of the critical components of corrosion monitoring is analyzing the samples taken from the process stream and reporting accurate and relevant data to the system operators. Caproco’s facilities include a full-service laboratory, staffed with trained technologists. Samples, such as corrosion coupons, are either sent in by clients or brought in by our field service crews.

The coupon numbers, locations (including positioning in the line), installation date and removal date are recorded; the coupons are cleaned either mechanically or chemically and then weighed. Final coupon weight is compared to its initial weight (stored in our database) and the weight loss of the coupon is determined. Using the weight loss and exposure interval, a corrosion rate can be mathematically calculated, and is reported in metal loss in mils per year (mpy) or micrometer per annum (uma). This data is then used to calculate information such as radial depth of pipe wall lost per annum.

In the case where pitting is identified, the deepest pit on the coupon is measured and a mathematical formula is used to calculate the pitting rate (in mpy).

A key advantage of in-house sample analysis is that lab technologists and service technicians can share information and analyze results together. Service crews can explain first-hand the condition of the coupons upon removal, the local operating conditions and any other information that often proves useful to lab analysis.