We have two installations – one with two 34SGs and one with four 50SGs. The sites have been commercial for about 1.5 years.
We use CorrShield NT4200 as a corrosion inhibitor and our raw water meets the requirements of the Wartsila manual. We also use 20% glycol in our cooling water.
After our initial cooling water fill, we had a pH of about 10.3 and in the past year it has dropped to about 9.5. The Wartsila recommended levels for pH are between 8-11 and tech services said to add NaOH to keep it within this range.
We plan on monitoring the pH and adding NaOH as necessary.
Are other users seeing the same trend in pH? How often are you adding NaOH?