How Hydropath Technology Reduces Corrosion

Current passing along a metal pipe creates a coaxial magnetic field, or “skin effect,” interfering with the electro-chemical reaction necessary for corrosion to take place. Introducing Hydropath Technology to a water system inhibits internal pipe corrosion by up to 65%.

Microbiologically Induced Corrosion

Microbiologically induced corrosion (MIC), is a mode of corrosion caused by microbes that reside in colonies (biofilm) or dispersed in water that cause the corrosion or influence other corrosion processes of metallic materials.

MIC is caused by bacterial microbes in combination with four other environmental conditions:  metals (host location), nutrients, water, and are usually anaerobic.  These bacteria are ubiquitous in the environment and metallic piping materials.  When all of these environmental conditions are present, then microbial growth will occur. 

When the nutrients in the system are consumed, the microbes may become dormant.  When the environmental conditions, i.e. nutrients are replenished, the microbial growth resumes. Water lines that develop scale may coat colonies of microbes that serves to protect them from biocides, and certain species that use iron as a food source can rapidly degrade pipes resulting in numerous pinhole leaks and eventually degradation of a majority of the piping.

 

A tube-in-shell heat exchanger shown before and after (Left/ Right) the application of the Hydropath signal, where not only has the limescale been removed but magnetite has begun to form as a hard black deposit.

A diagram showing how the skin effect reduces corrosion on the inner surface of the pipe.  

HydroFLOW Promotes the Formation of Magnetite

Hydropath technology acts against corrosion is to alter the way the oxides form. One type of iron oxide is known as magnetite. Normally this forms as a flakey substance, which then detaches from the pipe, allowing further corrosion to continue.  When hydropath technology is applied to a pipe, the magnetite forms in a rather different manner. 

Instead of forming as a flakey substance, the magnetite forms as a hard, black layer on the pipe surface. Because this magnetite has formed as a hard layer rather than as flakes, it acts as a barrier between the iron in the pipe and the water (particularly the oxygen in the water) and stops further corrosion. Rather than using chemical additives to form the helpful layer of magnetite, HydroFlow promotes the formation due to the sustained 150 kHz signal that emanates throughout the water system.

Reduction of corrosion due to skin effect When AC current flows through a pipe, the current flows just on the outside of the pipe, and there is no current flowing on the inside of the pipe. We now go on to see how this can reduce the corrosion that occurs on the inside of the pipe. Corrosion is caused by chemical reactions at the inner surface of the pipe between the pipe material and the water. Metal atoms in the pipe material become dissolved in the water. To do this they need to change from neutral atoms to charged ions - i.e. they need to lose an electron. The electron is then transferred to ions within the water.

With the Hydropath unit in place, any electrons that are released into the pipe by dissolution of the zinc are swept down the pipe by the Hydropath signal. Then by the skin effect they are forced to the outside of the pipe. This means that there are no electrons available for the chemical reactions to continue, blocking the reaction chain. This means the reaction cannot continue and therefore the corrosion stops.

 

An Example:

Water containing Hydrochloric Acid (HCl) passes through a pipe that is galvanized (i.e. coated with zinc Zn). When the corrosive reaction occurs, atoms of zinc in the metal become dissolved in the water. 

In order to dissolve, they have to give up an electron to become charged ions, so now there are two “spare" electrons in the metal. The metal does not like having too many electrons, and so transfers them back to the water by combining them with hydrogen ions (from the hydrochloric acid) to make hydrogen gas. 

At the end of this process, both the water and the metal have the same number of electrons as they started with and the process can repeat.