Preventing Water Contamination in your Heat Transfer Fluid System
According to an old adage, prevention is better than cure. There are a few measures you can take to prevent water from getting into your heat transfer system. These measures tackle the pathways that were described earlier in this article. Let us start with environmental sources. You should store pails, drums and totes holding your thermal fluids in a sheltered space away from the elements. At all times, these containers must be sealed tight. Where there is no indoor storage and outdoor storage is unavoidable, you should ideally place the containers sideways to prevent water from rain and snow from accumulating on the container tops. In high humidity areas, you want to be conscious of the operating temperature of your tanks. This must be kept above the dew point to prevent water vapor condensation. A Nitrogen blanket is also recommended for expansion tanks operating in humid regions. In these areas, it is also important to keep a lid on the tank of your Temperature Control Units (TCU). This prevents water vapor in the humid air from gradually condensing into the TCU tank.
Furthermore, we do not recommend hydrotests (with water) on heat transfer equipment. Compressed gases are a safer choice for pressure tests as far as water management is concerned. You can consider helium testing for example. Dye penetration and acoustic testing are other substitute testing methods that will not introduce water into your heat transfer system. In heat exchangers where water is run on the tube side, regular tests must be carried out to detect leaks and quickly plug leaking tubes where possible.
Finally, having a dedicated pump for your thermal fluids is worth it. It will prevent cross-mixing between any aqueous fluids and your heat transfer fluid. Appropriate and visible labeling of your inventory, lines and pumps will also help avoid common filling errors.