Riser tubes for automatic waterers
Most automatic waterers these days that require a water line to be run below the frost line will require a riser tube of some sort. By riser tube, I mean a tube to center the vertical portion of the water line in. So what is the reason for this and what can be used for this riser tube?
The overall intention for a riser tube is to prevent frost from carrying over to the waterline, thus resulting in slushy water or a frozen line. The supply line touching the riser tube is the most common cause of the supply line freezing. A common misconception is that if the riser tube is filled with insulation, wood or other foreign material, this will prevent the freezing. Since frost can migrate, any fill in the riser tube will only increase the chances of the lines freezing.
So what should be used for a riser tube? Many things have been used,