ASTM D7518 Standard Specification for 1,3 Propanediol (PDO) Base Engine Coolant for Automobile and Light-Duty Service
4. General Requirements
4.1 Engine coolant concentrates or prediluted PDO base engine coolants shall be formulated with 1,3 propanediol meeting Specification D7388, water, and suitable corrosion inhibitors, dye, and a foam suppressor.
4.2 PDO base engine coolant concentrates (Type I) may not contain ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol. Similarly, prediulted PDO base coolants (Type II) may not contain ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol.
4.3 All engine coolant concentrates or prediluted PDO base engine coolants shall conform to the general requirements given in Table 1.
4.4 Prediluted PDO (Type II) base engine coolants shall be formulated using water that meets the following requirements:
NOTE 3 - Prediluted coolants are intended for direct addition to an engine-cooling system with no further dilution. However, ifcircumstances require addition and prediluted aqueous engine coolant is no available, use the appropriate engine-coolant concentrate (Type I) diluted to 50 volume % with water of at least the quality outlined in Table X1.1.
4.5 When diluting engine-coolant concentrates for actual service, the water should be of such quality that it does not contain excessive solids, hardness salts, or chlorides. In the absence of specific recommendations from the engine or vehicle manufacturers, see Appendix X1, or Table X1.1. If such water is not available, use deionized (demineralized) or distilled water. This procedure will minimize the formation of hard-water scale and avoid the introduction of mineral components, such as chlorides and sulfates, which can increase the corrosion rate of aluminum and iron.
4.6 When installed in accordande with the vehicle manufacturer's recommendations and those on the product label, engine coolant concentrates or prediluted glycol-base engine coolants shall be suitable for use in a properly maintained cooling system (Appendix X1.1) in normal light-duty service for a minimum of one year without adversely affecting fluid flow and heat transfer.
5. Detailed Requirements
5.1 Glycol-base coolant concentrates and prediluted coolants shall conform to the physical and chemical requirements prescribed in Table 2depending on coolant type (see 1.2).
5.2 The requirements listed in Table 2 for prediluted coolant (Type II) are prescribed for the coolant as packaged, without further dilution or adjustment.
5.3 All coolant concentrates and prediluted coolants shall conform to the performance requirements listed in .
5.4 Coolant concentrates shall be diluted for performance testing as described in the individual ASTM test methods.
5.5 If necessary, the freezing point of prediluted coolants shall be adjusted with deionized water before proceeding with performance testing. The freezing point of prediluted PDO base coolants (Type II) shall be -27.8°C (-18.0°F).
5.6 Adjusted, prediluted engine-coolant performance test solutions shall be prepared as described in Table 3, Footnotes B through F.
6.1 1,3-propanediol; engine coolant; engine coolant concentrate; light-duty engine coolant; PDO; prediluted engine coolant