Text Box: ENGINE COOLANTS BOOK TABLE OF CONTENTS Text Box: TABLE OF CONTENTS Everything you need to know about coolants but couldn’t find anywhere. Until now! INTRODUCTION History, evolution and curve jump WATER AS A COOLANT Properties of water Operating temperature range Thermal expansion on freezing Heat of fusion Heat of vaporization Effect of pressure on freezing and boiling temperature Purity of water Distilled and de-ionized water Hardness Total Dissolved Solids Corrosive effects Acidity / Alkalinity Water quality requirements Water chemical analyses Examples of water chemical analyses COOLANT CONCENTRATES AND SOLUTIONS Antifreeze / anticorrosion protection Ethylene glycol Propylene glycol Chemical formulas Functional differences Toxicity of glycols THERMAL & PHYSICAL PROPERTIES OF GLYCOL & WATER SOLUTIONS Freezing behaviors of liquids - True freezing & supercooling Effect of EG concentration on freezing temperature Effect of PG concentration of freezing temperature Typical “anti-freeze container” freezing protection chart Thermal expansion and contraction of solutions Effect of glycol concentration on boiling temperature Effect of pressure / temperature on boiling temperature Effect of EG concentration on specific heat Effect of temperature on viscosity  BASIC CORROSION MECHANISMS Corrosion as a natural process Common manifestations of coolant failures Corrosion of ferrous metals Corrosion of non-ferrous metals Electrochemical corrosion Galvanic activity Galvanic series of metals Electrochemical corrosion mechanisms Anodic Reactions Cathodic Reactions Corrosion cells Bi-metal corrosion cell Single metal corrosion cell Electrical conductivity of electrolytes Sources of electrical currents in the cooling system Acidity / alkalinity (pH) Effect of pH on the corrosion of metals Reserve coolant alkalinity Survey of coolant Ph Effect of pH and electrical potential Electrolysis Electrolysis demonstration with conventional coolant Electrolysis demonstration with organic acid coolant Pitting corrosion Crevice corrosion Solder corrosion (bloom) Uniform corrosion Effect of dissolved mineral salts on corrosion Effect of dissolved oxygen and combustion gas on corrosion Effect of relative surface areas on corrosion Effect of aggressive ions on corrosion Effect of metal temperature and heat transfer on corrosion Effect of homogeneity of tube material on corrosion Effect of deposits on corrosion Copper/brass radiator corrosion Liquid erosion, cavitation Liquid erosion, impingement Laminar and turbulent flows Erosion patterns in the radiator tube array  CORROSION INHIBITORS Corrosion inhibition Evolution of inhibitor formulations Inhibition mechanisms (anodic, cathodic and adsorption) Chemistry of the inorganic inhibitors Silicate Amines Nitrite (NO2) Nitrate (NO3) Borate Phosphate Molybdate Carboxylic organics acids + polymers Inhibitor / Function Summary chart  TYPES OF COOLANTS Inorganic (conventional) coolants Light duty vehicle coolants Heavy duty vehicle coolants Imported vehicle coolants Propylene + inorganic additives Plain water + inhibitors Non-aqueous propylene Organic Acid Technology (OAT) coolants Hybrid (HOAT) coolants HD HOAT coolants Cooling system water filters Chemical water filters (slow release mechanisms) Supplemental coolant additives (SCA’s) Radiator cleaners and flushes Effect of stop leak pellets Storage and handling of coolants Compatibility of coolants  RECYCLED COOLANTS Environmental and economic considerations Recycling processes Simple filtration Filtration + chemical ion exchange Distillation Reverse osmosis Impact of legislation on recycled coolants COOLANT STANDARDS (ASTM) LISTING OF REGISTERED COOLANT VENDORS  SERVICE PRACTICES Estimating glycol solution concentration Specific gravity Hydrometers 5 ball “eyedropper” type Pivoted float type Refraction Refractometers Accuracy of solution concentration measurements Measurement of pH  APPENDIX A Cooling System Flush Water Disposal APPENDIX B Prestone United States OAT Patent 6,143,243