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Closed Loop System Recovery Plans for Commercial Water Treatment

By: Ben Feeney

Turbulent water containing high mineral content wreaks havoc on systems causing closed loop systems to literally "take a beating." As time goes by, leaks may develop, causing more water to be introduced to the system to replenish the loss. This make-up water further introduces oxygen and minerals to the system. When water’s “state of balance” is disrupted by the influx of minerals and debris, corrosion is likely to occur.


Have you tested your water recently for Total Dissolved Solids, pH, bacteria, iron, copper, aluminum, or chemical corrosion inhibitors?

What happens when we test and find the water is full of iron, mud, sediment and /or bacteria? Left unchecked, high iron may erode pump seals. Microbiological issues often accelerate the corrosion process by causing the pH to drop locally. Pinhole leaks, pitting and heat exchanger fouling are all symptoms of dirty, untreated water.


This is why we have developed the Closed Loop Recovery Plan.”

“Recovery” is the key word here.


The goal is to “Recover” the system water back to specification by following these five steps:


Step 1: Sample and test the water to determine what levels are out of specification for a given system.
  • When high amounts of suspended solids, ironm and bacteria are present, move to step #2.

Step 2: Add organic and inorganic chemical dispersants:
  • Incorporate Boland’s (C-359 and B-857) to tie up and re-solubilize dirt, iron, calcium, and other debris off the pipe. Allow these products to circulate for several days to transport as much debris as possible.

Step 3: FLUSH!!! Purge the system from a low point in the system at about 2-4 gpm. It may take a few days to a week to get the water clear. This depends on the system volume.
  • Step flushing when the iron levels are below 1ppm and the water quality is close to city water.

Step 4: Add Corrosion Inhibitors (LoopGuard 505) to protect mild steel and copper. Add pH adjustment buffers to get the pH back into the typical alkaline range of 9.5-10.0. Add a non-oxidizing biocide such as Boland’s (AA-4215) to kill off bacteria that may be present.

Step 5: Install a cartridge filtration system (Link to Shelco) to physically remove and polish off trace iron, silt, sand, and other debris from your system. PM filters on a regular basis.

By following these steps, you will “Recover” and bring your water back to its original specification. Your equipment will thank you for it. Get started with a free consultation by completing the form below.



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