Urgent question: What material is suitable for pumps used with frozen saline (calcium chloride solution)?
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This post was last edited by sunjl1981 on 2013-1-6 23:15. What material is suitable for pumps used in frozen saline (calcium chloride solution)? Carbon steel or stainless steel? How corrosive is a calcium chloride solution exactly? Most of our friends suggested that we use stainless steel, and since we have a large number of items, this is quite important. Urgently need discussion, thanks. The concentration of calcium chloride solutions ranges from over 10% to over 20%, and there are three temperature systems: -35°C, -15°C, and 0°C. # ， ， &
Use stainless steel! After the concentration of the calcium chloride solution is adjusted to the required level, a corrosion inhibitor is added.
Ordinary carbon steel will do; that’s what we use in our factory currently. It works the same whether at -35 degrees or 0 degrees
Our company uses 16MnR, which is resistant to low temperatures.
Our company also uses 16MnR.
Suggestions: 1. The corrosivity of calcium chloride solutions increases at low concentrations; it is best to keep the concentration at 30% at both -35 and -15 degrees Celsius, and an IS pump made of ordinary carbon steel will suffice； 2. For water at 0°C, ethylene glycol solution is the best choice as it is non-corrosive.
Boss! A reminder for you! Use stainless steel; don’t blame me. Spend money where it counts! Carbon steel and stainless steel were compared in calcium chloride solutions as well as in calcium chloride solutions with corrosion inhibitors added; carbon steel suffered significant corrosion, and this corrosion was reduced in the solution containing corrosion inhibitors. Stainless steel showed slight signs of corrosion in the calcium chloride solution, but almost no such signs were observed in the solution with corrosion inhibitors added! ! ! This post was last edited by yzhms on 2008-4-4 18:18]
Adding a little corrosion inhibitor is sufficient for carbon steel; ammonia refrigeration has been in use for many years. Stainless steel cannot be used, as it will corrode and cause leaks. This post was last edited by yzhms on 2008-4-4 18:17]
Do you have any theoretical basis for this? I suggest you find out about the impact of chloride ions on stainless steel materials, okay? OP, it seems that someone on this forum mentioned something similar regarding the use of titanium pumps for sodium hypochlorite.
Thank you to all the friends above for their sincere suggestions. After comprehensive comparison and analysis, and particularly by taking into account the opinions of the manufacturers of refrigeration units as well as the choices made by most of their users regarding salt water pumps, the initial preference is to use stainless steel, along with a corrosion inhibitor. At 09:00, the company will hold a discussion session to specifically examine the choice of this material; the results of the session will be shared with everyone later. :) Thank you again to all the experts.
There is no need to use stainless steel; pumps made of carbon steel will do, and our company has been using them for over twenty years.
Ordinary carbon steel will do
Results of the seminar announced: Stainless steel pumps will be used for the salt water pumps in the -35 and -15 degree systems, while carbon steel pumps will be used in the 0 and 7 degree systems. Mainly, the carbon steel pumps currently used in our factory exhibit cold brittleness at low temperatures, and the corrosion of stainless steel by chloride ions requires certain conditions. This topic will be explored in greater depth once an appropriate theoretical basis is found.
A regular water pump can be fitted with a corrosion inhibitor (sodium chromate).