... .This water storage tank could be designed with single coil, double coils and three coils, with one innter tank or two inner tanks ... no.PCIN080617).It is made of high quality stainless steel with advanced welding, and formed by high pressure polyurethane resin. Central ... of Inbuilt coils or out-looped coils for choice* Couple with boiler, electric heater, heat pump or solar heating system * Separated ...