Water chiller flushing

[digerious]

I haven't worked alot on water chillers, and a customer has flushed out his water chiller a few times with water, but is still getting corrosion sediment coming through. He is asking if this might be a problem in the future, and if there is anything more effective than water to flush out the system, and also is there a product available that works as a preservative when added to the glycol solution. Thanks in advance. Chris.

[chemi-cool]

the water might getting the dirt elsewhere.
If its only rust, there all sorts of protective solutions that you add to the dirty water to protect the steel parts.
First you must analyze the water and find out what is that dirt.

[digerious]

Thank. Turns out the customer has had leaks, been topping up with just water.

[frank]

The rust will be from the interaction between the oxygen in the water and the iron in the pipework. The glycol mix will not prevent this as it is there to lower the freezing point of the water only.

Once flushed (removal of debris), and once refilled, the system will require the addition of an 'inhibitor' which will reduce the oxygen/iron reaction. If the chiller has a shell and tube heat exchanger then you should also look for scaling caused by calcium deposits in the water.

As Chemi suggests, get a proper water analysis done to determine what type of treatment the chilled water system needs.