Cooling tower leak

[ddalberto]

Big inn and spa. Five years ago new maintenance man shuts down cooling tower for the winter and freezes the coil. We replace coil. $30,000 job. Poor maintenance no water treatment. Water leak underground for a year that they don't address. Water make up running full open to keep loop charged. Get called this week. Coil leaking (rust hole). You can see the picture. (The picture is looking down into the tower with the decking removed showing the coil). The galvanized tubes are all corroded all ready.
Any ideas why? I did set them up with a good water treatment guy that has been on them to repair the leaks from the last year so he could treat the loop. He is stumped as of right now and looking into what the corrosion is from.

Time for a new tower....thank God winter is coming.

[alcomech]

Electrolysis

[ddalberto]

Where would the electrical current be coming from to creat electrolysis ?

[alcomech]

You will need to verify that the building and equipment is properly grounded. There are many instances when equipment is failing and insulation of motors has deteriorated that voltage leakage is present. This is leakage is very low and is usually no more than a few Milli-amps.

I am not saying that this is the problem altogether, but needs to be considered.

You definitely want to check the PH and condition of water treatment.

[ddalberto]

Thats one direction to look thanks.

[valdelocc]

It could be something in the air side, like exhaust from dryers.

[Phmteck]

Not sure of your setup , the water guy should be able to answer that question if he really is a good treatment guy. I've had a cooling tower underground tank leak and contaminate the loop water causing major corrosion problems. The water guy should first be checking pH conductivity and other water parameters. the water bill must be astronomical but, The customer doesn't seem to mind though he already got hit with a 30k tab. If your adding heat to the loop water and it's not treated. plan on replacing that tower every couple years.

[ddalberto]

They are adding heat to the loop water. Water treatment guy is very reputable but no use treating water going down the drain. Water bill through the roof. Very rich customers... More concerned with the appearance of the place. Don't listen to anything. Water treatment guy came up with a possible theory on electrolysis. They were using city water from hose with a brass end to constantly over flow sump to keep with load....brass....galvanized pipe.....? Possibility ? Tower is way undersized. Have to put in new tower but don't want this to happen again..

[wolfdog]

If the make-up is running wide open to keep up with the leak, chemical use must be enormous also. It's hard to treat water that is constantly being diluted.

[mikeacman]

If the make-up is running wide open to keep up with the leak, chemical use must be enormous also. It's hard to treat water that is constantly being diluted.

+1,,given there is evaporation and drift present and make up is inevitable and part of it a huge leak will imitate a larger loop/tower and consume that much more chemical.... But then again im not sure evaporation removes chemicals the same as a leak whether it be stuck open blow down ,overflowing or a busted pipe...

Electrolysis or improper or impossible water treatment...

[ddalberto]

To top it all off the two boilers have aluminum heat exchangers. Water treatment has to be perfect for that. This place is a disaster.

[wcsmith]

This could be caused from a number of issues, but the first thing to start with would be to consult a good reputable water treatment provider. Second, was the coil passivated once the new coil was installed? This appears to be an EVAPCO coil so you can find information relating to passivation and water treatment at the company’s website.