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Coolant Ph

Posted: Tue Jan 31, 2012 9:09 pm
by BilgeRat1
Does anybody have any idea of what Ph I should be looking for in an EMD 645 cooling system running Nalcool 2000 and no antifreeze?

Re: Coolant Ph

Posted: Thu Feb 02, 2012 5:37 am
by JollyJack
In general, when pH points to acidic environment, the chances for corrosion increase and when pH points to alkaline environment, the chances for scale formation increase.

The pH values above 7 signify alkalinity, pH values less than 8.3, most of the alkalinity in the water is in the bicarbonate form, and scale formation is normally not a problem. However, when the pH rises above 8.3, the alkalinity converts from the bicarbonate to the carbonate and the scale will start to form. You want to keep the water alkaline, but not too alkaline. 10 or 11 is great for boilers where scale inhibitors are added to water treatment, but cooling water should be in the 8 - 8.5 range, not more than 9. Nalcool 2000 is particularly suited for small medium speed engines like the EMD (which, in my opinion is the best medium speed engine ever made, designed to be run and maintained!) and the recommended concentration of that chemical additive will maintain Ph in the required range.

You might want to keep an eye on other parameters, too, eg:
Total hardness, 170ppm Max
Chlorides, 40ppm Max
Sulphates, 100ppm Max
TDS 340 Max (Total Dissolved Solids)

Your Nalcool supplier should be able to provide a suitable test kit.

Re: Coolant Ph

Posted: Thu Feb 02, 2012 10:04 am
by The Dieselduck
Attached is the EMD notes on Coolants. They don't make mentions of the pH exactly, but there is some reference in there.

Re: Coolant Ph

Posted: Sat Feb 04, 2012 9:30 pm
by BilgeRat1
Thanks guys. We have had no way of testing coolant since about 2007; seems they didn't put too high of a priority on finding a way for us after Dearborn's little conductivity testers went away. This past trip out, we got test strips that also checked Ph, so I was curious. My Ph came in at about 8, and minerals are not a problem as we run a water softener on board. We treat with Nalcool 2000. Chalk this one up to blind luck, but my Nalcool levels were at the recommended levels on everything except the SME, and it only needed a gallon to bring it up to spec. Good to know it's all good,

Re: Coolant Ph

Posted: Sun Feb 05, 2012 12:37 pm
by Big Pete
Good, always welcome to hear the results after people ask questions.