Controlling corrosion in closed loop systems is one of the main goals of the water treater, to make sure the loops can operate as designed for heat transfer without any inefficiencies or leaks. A common issue found within closed loops for manufacturers can be high copper levels. And that was the case with manufacturer in a Central OH facility. They were consistently seeing high copper level results, hovering around the 4-6 ppm range.
Copper levels that high in closed loop systems are often a result of the water corroding the copper piping, scraping off the copper ions and bringing them in solution in the water. The problem with these high levels of copper ions in the water, is that they will precipitate out and corrode the other metals in the system. Oftentimes causing galvanic corrosion of steel, making control of copper levels important for longevity of the closed loop and heat transfer system.
The key in any corrosion protection for your equipment is to know and trend water analysis to get out ahead of any potential corrosion issues. In this case, Chardon noticed the copper numbers rising and started an assessment of the system to find any potential red flags.
Through monthly testing of the loop water and a flush of the system, our service technician noticed that the loop chemical, a phosphate inhibitor, was not protecting the material in the loop itself. The inhibitor was stripping the metals off the loop, exposing the copper and other yellow metals along with steel.
The first step to preventing the continuous copper corrosion was for a change in inhibitor to better protect the metal from corrosion. Each application is different, even within a single industry like manufacturing. Knowing information such as the metallurgy of each system, system volumes, temperatures, and make-up water quality, and designing a water treatment program around the specific needs of the system is the only way to protect the life of the equipment.
The new inhibitor did not take any deposits off the metal, keeping the pipes free of corrosion. The other step was putting the loops constant flush to remove the excess metals, until the water in the closed loop system was down to a safer level of metals.
The switch in chemical and the dosage of the chemical helped better protect this loop system and stopped the copper from being stripped off into solution. The loop that had consistent copper numbers in the 4-6 ppm range, over the next few months dropped to a 0.2-0.4 ppm range. This dramatically reduces the risk of the galvanic corrosion caused by an excess of copper ion in water. Knowing the right closed loop chemical that will safely protect the metals in the loops is crucial. Contact us at Chardon today to help treat your closed loops and protect them from corrosion!
