Most automatic drinkers these days, which require a water line to run below the frost line, will require a riser of some kind. By this, I mean a tube to center the vertical part of the water line. So what is the reason for this and what can be used for this standpipe?

The general intention of a riser is to prevent frost from moving to the waterline, resulting in muddy water or a frozen line. The supply line touching the riser is the most common cause of supply line frostbite. A common misconception is that if the riser is filled with insulation, wood, or other foreign material, this will prevent freezing. Since frost can migrate, any fill in the riser will only increase the chances of the lines freezing.

So what should be used for a riser? Many things have been used, larger PVC pipes, concrete pipes, just to name a few. However, none of these materials will provide maximum protection to the automatic waterer during winter.

Iowa State University in Ames, Iowa, conducted a study during the winter of 1992-1993. Their studies indicated that an insulated water supply line helped keep temperatures above freezing. The same study showed that insulated water supply lines with an 8 “ID and 12” OD provided optimal freeze protection and sufficient access for service. They found that this size would help retain heat from the water as it passed through the waterline. This helped prevent freezing even when the ambient temperature was well below freezing. A second part of this study also showed that there is no heat from the ground going up the heated tube to the automatic sprue and that the heat from the ground cannot provide enough heat to prevent the sprue from freezing.