Why Treat Hot Water Closed Loop Systems?

The most common problem in either a hot water boiler system or a converter system is corrosion. Corrosion can be caused for the following reasons:
 
A- High oxygen content:

As all minerals, such as iron, are found in nature as the oxides, it is normal for iron, for example, to try to find oxygen and change to iron oxide. This type of oxide is red in colour. Oxygen is usually dispelled from the systems fairly quickly through the air vents; however, where there are large losses causing a large make-up condition, we then have a continuing supply of oxygen and trouble.

Oxygen or air can also get into the system from the cushion tank and also due to a low pressure on the system at the top. The most important thing to do is to correct the condition causing the large amount of air getting into the system.

B- Electrolysis or galvanic action:

Is actually the evolution of oxygen by the action of direct current on water. This current is developed between two different metals, hence is called dissimilar metal corrosion.

We can have a current when we have a stress developed in a metal of the same analysis. In these reactions a small amount of metal is removed from the cathode (the cathode is the metal lower on the electromotive scale).

The metal, e.g. iron (Fe) then combines with the oxygen formed by electrolysis and a black, magnetic deposit is formed - also a hole in the iron pipe. It should be noted that nothing happens to the other metal, for an example, in a copper-iron situation.

The copper is unaffected and the iron is removed into solution. The treatment is to isolate the locations of dissimilar metals with dielectric isolation and treat with cathodic corrosion inhibitors.

C- Dirty Systems:

By dirt, we mean either garden type dirt, oil or corrosion product, iron oxide. The presence of dirt does two things: it can cause a cell action and itself cause corrosion and it can and does prevent the corrosion inhibitor from coating the metal.

This can mean that the corrosion inhibitor appears not to work as well as it should.

D- Combinations of all three above:

 We can, and do have combinations of all of these conditions.

Chemical Feeding:

In average size systems the chemicals is fed by means of a by-pass feeder located wither across a pump or across a valve. The feeder should be at least 1½ gal. in capacity and fitted with a strainer.

In large systems that is, over 10,000 gal. capacity, we would suggest a chemical feed unit consisting of a 45 gallons tank, agitator and a piston type chemical feed pump. With this set-up you can feed a number of systems from the one pump and tank.

One of the best treatments is the use of our product S.H.W Concentrate for full protection.