I am installing a boiler with an aluminum heat exchanger in an old steel piping system. I am having a lot of trouble getting the old system clean, which is causing my pH to creep. The pH must be kept between 6 and 8.5 in order to protect the aluminum. I know that this is different from the desired condition for the mild steel piping. I'm told that 9 or 10 is a common pH level.
We have filled and flushed the system numerous times and circulated cleaners. I don't know exactly what was used, but we have hired one of the local leading water treatment companies to do this for us. They seem perplexed, which is causing me a lot of stress. I understand that the cleaners are typically alkaline based, so I suggested (and I know next to nothing about chemistry) that they try an acid-based cleaner to "shock" the system a little and knock off any scaling. They gave me the impression that I had a good idea ----- so why didn't they think of it???
The problem is that we have achieved 8.5 pH, but it then creeps up. I'm told that's from the pipe reacting to the new pH level after being exposed to much higher levels for many years. This reaction is driving the pH back up.
Anyone ever come cross this? In my mind, I would just keep introducing acid until the pH comes down, but I'm sure there is more to it than that.
Any thoughts?
We have filled and flushed the system numerous times and circulated cleaners. I don't know exactly what was used, but we have hired one of the local leading water treatment companies to do this for us. They seem perplexed, which is causing me a lot of stress. I understand that the cleaners are typically alkaline based, so I suggested (and I know next to nothing about chemistry) that they try an acid-based cleaner to "shock" the system a little and knock off any scaling. They gave me the impression that I had a good idea ----- so why didn't they think of it???
The problem is that we have achieved 8.5 pH, but it then creeps up. I'm told that's from the pipe reacting to the new pH level after being exposed to much higher levels for many years. This reaction is driving the pH back up.
Anyone ever come cross this? In my mind, I would just keep introducing acid until the pH comes down, but I'm sure there is more to it than that.
Any thoughts?
