Dynamax HPFM3, Installation And Operation Manual, Page: 30 / 86

Photo 3
Refill Kit
Revision: JUNE 2017 30
5.4 Adding De-gassed Water to the HPFM
The Captive Air Tank (CAT) is a two-compartment tank. The upper compartment contains water and the lower section
can be pressurized with air. A flexible rubber diaphragm separates the two compartments. The large stainless steel CAT
allows you to pressurize the water without the air and water mixing together. The CAT will hold 7.0 liters of water and it is
best to refill while there is still at least 1.0 liters of water in the tank. If the CAT is initially empty then refer to
Subsection 5.4.2,
“ Priming a totally empty tank.”
Normal tap water or water that has been standing naturally absorbs air. The particles in naturally found water and/or tap
water plug the very small inner diameters of the tubing used in HPFM as well.
CAUTION!
Always use Distilled Degassed Water in the HPFM.
If the dissolved air effervesces, or the air comes out of solution (much in the same way a soda pop will effervesce when
the can is opened), then air bubbles will form. These air bubbles will compress as the pressure increases. However, when the
water is flowing from the HPFM and the pressure decreases, the air can come out of the solution. Air and water behave
differently when compressed, or pressurized. Water, for the most part does not compress, with its volume changing little. Air
will compress with great changes in the volume that the air occupies. That large change is why air must be removed
from the HPFM system.
The water added must have the air removed. There are two accepted ways for removing the absorbed air from water.
The easiest way is to “boil” the water or raise the temperature of the water to the vapor point of water 100° C (212 °F.)
However boiling removes less than half the air. A more effective way is place the water
in a vacuum. Degassing the distilled water is explained in Subsection 5.4.1 ,
“Making
Degassed Water / Preventing Algae Buildup Inside the HPFM.”
Your HPFM system comes with a HPFM refill kit. The refill kit is a 7.6 L (2 gallon) tank that
can be pressurized by pumping air with the handle on the top of the unit. This pressurization
will force the degassed water into the CAT of the HPFM when connected. The Refill Kit
tank conveniently allows refilling of the HPFM just about anywhere.
There are a few important things to remember about the HPFM. The first is to always
visually check the level of the degassed water in the HPFM Refill Kit. The degassed
water level should never go below the siphon point inside the Refill Kit tank. If air
were introduced into the HPFM system during filling, then this would mean removing
the air ‘and follow the procedures in Section 5.5, “
Eliminating Air from the HPFM
.”
CAUTION!
If degassed water is kept in the refill container more than a few minutes under
pressure it will become supersaturated with air again. So fill immediately after
degassing!