The intermediate frequency furnace inductor cooling water should be clean and free of impurities. The solid content is not more than l0mg/L, and the water resistivity should be 2.5xl000 a.cm. It is easy to precipitate due to the large amount of insoluble salts in the water with too much hardness. Scale is formed , so the total hardness is not more than 2.8mg / L, the sulfite and chloride content is not more than 50mg / L, the cooling water should be soft water with low hardness , preferably using distilled water to minimize the formation of scale. 

A closed cooling water system , such a system having two circulating water system , an outer loop is open recirculating water system , the water circulation system is a closed loop , during which water - water heat exchanger to transfer heat , the circulation using soft water and distilled water , easy to deal with water quality , system stability , low operating costs , the external loop water less demanding. Therefore, the life of the inductor can be greatly improved.