Water Quality Specification
Though often taken for granted, the quality of water mixed with glycol concentrate can have an enormous impact on system performance. Marginal quality water can lead to the development of scale, sediment deposits, or the creation of a sludge in the heat exchanger which will reduce heat transfer efficiency. Poor quality water can damage the system by depleting the corrosion inhibitor and promoting a number of corrosions including general and acidic attack corrosion.
Since it is vital to use high quality water for glycol dilution in order to maintain system efficiency and prolong fluid life, you must ensure your water is of sufficiently high quality. Good quality water contains:
- Less than 50 ppm of calcium
- Less than 50 ppm of magnesium
- Less than 100 ppm (5 grains) of total hardness
- Less than 25 ppm of chloride
- Less than 25 ppm of sulfate
Check with your county or city water department to determine the chemical properties of the local water. If the dilution water will be drawn from a well, which typically has extremely hard water, or the local water authority cannot provide an accurate profile, we recommend either testing the water yourself or hiring a commercial water treatment specialist to analyze the water.
A simple test to ensure that the dilution water contains less than 100 ppm of hardness, is to fill a small sample bottle with 50% glycol and 50% water. Let the solution stand for 8-12 hours, shaking it occasionally. If any whitish sediment forms, the water is too hard and should not be used to dilute the glycol.
In those cases where tap water does not meet the standards for quality, CORECHEM Inc. recommends using demineralized water that has been distilled, deionized, or passed through a reverse osmosis process to remove harmful minerals and salts. A suitable corrosion inhibitor must be used with demineralized water since the pH of the treated water may be measurably less than seven.