HYDRO-TREAT Hydronic Water Treatment

PRODUCT FEATURES

The goal of CH2O HYDRO-TREAT series products are to protect engineered hydronic systems. The hydronic system is a continuous enclosed volume of water consisting of tanks, heat exchangers and connecting piping. These systems are used to transport energy. Dissolved oxygen in the enclosed water is known to attack construction metals. Also, biological activity is known to infect these systems and attack ferrous alloys. CH2O HYDRO-TREAT series products are designed to minimize the occurrence of metal corrosion. These products, together with CH2O BIO-BLOCK series products to prevent biological growth, create a comprehensive program to give lasting life to the hydronic system. This program reduces maintenance costs and extends system life time.

The loss of metal creates pits that can rupture piping; causing a loss of water and undesirable water entry to processes and building areas. Careful analysis of the water and the system components determines how the water may be treated. A treatment of CH2O HYDRO-TREAT sequestrant/inhibitor provides a major reduction of oxygen attack. The following chart shows the relationship between the amount of oxygen dissolved in water at various temperatures.

APPROPRIATE APPLICATIONS

As can be seen in the above chart oxygen can dissolve into water that is at temperatures less than the boiling point. The operating temperature of hydronic systems is normally below 212 degrees F. The oxygen in the water reacts with metals to form soluble and insoluble oxides. Although the oxygen content is lower at elevated operating temperatures, the reaction rate is increased. CH2O HYDRO-TREAT products use several components to prevent the oxygen from contacting metal.

Often the operating temperature is cycled as in a building heating and air conditioning system. The water in such systems under-goes expansion and contraction. During the expansion phase water is forced out of the system. Provisions can be incorporated to contain the added volume. During the cooling phase, air and make-up water will be drawn into the system. Expansion volume provisions may return water to the system to alleviate the situation. However, even a well designed system still receives enough oxygen to cause a problem.

Heat release devices such as space heating radiators require air elimination. Air pockets in the radiator prevent hot water from contact with the radiator metal. Air elimination is provided by mechanisms such as miniature float valves that allow air and any other gasses to escape the system. It is during the contraction cycle that air can be drawn into the system through these devices if system pressure is insufficient. Circulating pump seals are another source of air intrusion into the system; especially in older systems that have not been properly maintained.

PROTECTION METHOD

There are two methods generally used to control oxygen in an hydronic system. CH2O HYDRO-TREAT uses the method of inhibiting metal surfaces. The other method used is the addition of oxygen scavengers to consume oxygen. The inhibitor method is more economical than oxygen scavengers because inhibitors are not consumed. Repeat addition of inhibitors is not as frequent as what is necessary when scavengers are used.

Most systems are constructed of both ferrous and copper alloys. It is necessary to protect at least these two general types of metal. The product managers of CH2O have developed blends of several materials to produce a comprehensive protection program. These products have been tested and evaluated since 1977. The result of this effort is a series of products that have proven outstanding performance. How this is achieved is illustrated by this figure:

Two or more materials are used to create a mono-molecular film on both iron and copper. These materials have been selected for durability of the film. Selection of materials are based, also, on the amount of material needed in the circulating water necessary to produce a complete film.

CH2O HYDRO-TREAT products include the technique of adjusting water pH. The Langlier Stability Index predicts that higher pH levels reduce the potential of water to be corrosive. The CH2O HYDRO-TREAT series includes materials which buffer, or adjust, the pH to desirable levels. pH buffering plays an important role in conjunction with the film forming materials, as these films are stabilized by suitable pH levels.

Hydronic Water Treatment Product Bulletins