Dissertation work is devoted to study of processes of internal corrosion in hot water supply systems with mild steel piplines, development of methods and means of corrosion monitoring and corrosion protection. It is established that the steel corrosion products are electrochemically active, which complicates the application polarization resistance method of corrosion monitoring in the hot water supply systems. The values of the constant that relates polarization resistance to corrosion rate were determined experimentally depending on exposure duration, flow rate and temperature. It is established that introduction of magnesium ions in the tap water by anodic dissolution of metal anode leads to a reduction of corrosion rate of mild steel with the formation of compact aragonite precipitation under the influence of Mg2+ cations, reduction of dissolved oxygen content and growth of pH due to the cathodic reduction of oxygen. It is revealed that after the formation of a dense layer of corrosion products on steel appears inversion between corrosion rate and flow, the growth of flow rate reduces corrosion. The increase in the rate of water flow in the pipeline to 0.45 m/s helps reduce corrosion rate of steel up to 0.1 mm/year and below. Developed portable corrometer PIK-2 and stationary corrometer SIC-3 for corrosion monitoring based on polarization resistance method in water supply systems. On the basis of stationary corrometer developed system of the automated corrosion monitoring that can handle up to 8 corrosion probes, to back up the results of measurements, to transfer data to the PC for processing and analysis, and control the means of corrosion protection. The new magnesium protection units from internal corrosion of the pipelines "SCHIT-N" was developed featuring increased reliability of anode fixing, the transfer of corrosion probe to the input of installation, using as a flow sensor of impeller water meter with pulse output and the introduction of the sensor for determining the anode consumption. The carried out industrial tests of magnesium protection unit "SCHIT-N", showed the high efficiency of this method of protection. Keywords: hot water supply system, corrosion rate, surface films, linear polarization resistance, corrosion monitoring, portable corrometer, stationary corrometer, goethite, electrode capacity, magnesium anode, magnesium hydroxide, magnesium protection unit, magnesium protection, corrosion protection.
