Using Tap Water in Radiator
Water is an excellent medium for heat transfer. Then why not use plain tap water in the cooling system of the diesel engines instead of the branded Coolants available in the market?
Although water is one of the best mediums for heat transfer, it has got some limitations.
Water will start boiling as soon as the temperature reaches 100oC and will evaporate in the form of steam. To increase the boiling temperature of water the cooling system is designed as a closed-loop system equipped with a Pressure Cap in the Radiator. The concept is similar to that of a Pressure Cooker. By chance, if there is a leak in the Pressure Cap of the Radiator, the water will evaporate at 100oC, if not refilled in time all the water will vanish and the engine will seize due to high temperature.
Water freezes at 0oC, it will not work in sub-zero ambient temperatures. The water will freeze and block the coolant passages and will also damage the Water Pump.
Water is corrosive when it comes in contact with ferrous metals. It will form rusts throughout the coolant flow paths and eventually choke it. At very high temperature water also corrodes aluminium and copper parts.
The minerals and other impurities present in water also contribute to scale formation along the paths of coolant flow. The fine water tubes of the radiator will get choked severely.
Rust and scale formation completely destroys the cooling efficiency and finally the engine will seize due to lack of cooling. Only a costly and time-consuming engine overhaul service can restore the engine in such cases.
That is why specially formulated Coolants are used in engine cooling systems. Various chemicals are added into the water to make the coolant which is most suitable for the engine.
