Corrosion of the chilled water pipes in refrigeration units
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This post was last edited by sunjl1981 on 2013-1-6 at 21:35. Our chiller units use pure water for the chilled water supply, and the pipes are made of carbon steel. The impeller of the pump has been replaced twice recently. They have all been corroded. Pipelines also suffer from corrosion. Could you tell me what’s going on? What kind of water do you use? The temperature is 10 degrees. # + + . hcbbs
The chilled water used in our company is also pure water, but this issue has not occurred there. Has the water quality of the chilled water been tested, as mentioned by the poster? Check the current water quality
Reply to 2# wz16: We used pure water as the cold medium, and no problems arose with that. I guess when it is used as a cooling medium, there might be leaks in the equipment that needs to be cooled, causing the coolant to mix with pure water and thus causing corrosion to the pipes and impellers； Or there is a problem with the material of the pump’s impeller ； Check whether the internal corrosion of the pipeline is caused by prolonged flushing with pure water; for reference only
Soft water should be used instead of pure water, as pure water can easily corrode carbon steel.
Corrosivity is the rate at which electrochemical reactions occur. We once conducted a small experiment by soaking small iron pieces in pure water and tap water for comparison. The result was that the iron pieces soaked in pure water suffered more corrosion than those in tap water. Generally, pipes used to carry pure water are either plastic or stainless steel, and the pumps used to deliver pure water also need to be made of stainless steel. The reason pure water is corrosive is likely due to the higher reactivity of oxygen molecules in it
If pure water is being used, then why are carbon steel pipes employed? Can this still ensure the purity of pure water?
Is pure water corrosion caused by a low pH value or by oxygen corrosion? Our pH level is currently between 10 and 11; we would like to consult the experts again
It would be best to conduct a water quality test for pure water, to determine the level of chloride ions in it
I have a gentle question: which area is the chilled water station supplying?
It is best not to use ordinary carbon steel for pure water pipelines, otherwise the pure water will become impure. It is recommended to use non-metallic pipes or stainless steel pipes.