 CTS-5 Test Shop Water to ASTM Water Quality Recommendations Introduction  Proper coolant system maintenance requires a quality make-up water.
All make-up water is corrosive but water with high mineral content cannot be made fit for use. As soft of tap water as possible should be used.
Tap water that has been softened by some type of salt or chloride process should not be used.ASTM Water Quality Recommendation (from D-4985):
Threats to Make-Up Water Quality Calcium: combines in engine coolant to form scale on hot heat exchange surfaces. Scale is an efficient insulator, and the result is localized engine overheating that can cause component failure. Magnesium: Magnesium also can form scale, creating localized overheating and warped engine heads. It is the second of the two components (with calcium) measured to determine the degree of "water hardness". Water that contains calcium and magnesium is defined as "hard"; the concentration of the two chemicals combined determines the level of hardness. Silicate: In water, silicate would be detected as the result of sand, not sodium silicate inhibitor. Sand is frequently found in cooling systems, and is associated with premature wear due to abrasion in various areas of the cooling system. Chloride: Municipal drinking water most often is, in fact, acceptable for engine coolant. A water test can determine the quality of municipal water. Nevertheless, most municipal waters contain chlorine, resulting in the formation of chlorides in the coolant. Chlorides are aggressive to aluminum. Oxygen: Anyone who has tried deionized water knows it tastes nasty. This is due to its lack of oxygen. Oxygen contributes tremendously to metal corrosion and depletion of inhibitors. City water is full of oxygen making it suitable for drinking and keeping pet fish. Water with low oxygen levels is preferable for coolant.  Procedures
|
