Can I install a submerged check valve under the float valve in a cattle water trough without backflow preventer to prevent freezing in winter?
Asked by Ömür Tunçeri 
3 months ago
Last Updated: October 9, 2024
Hey plumbers, I’ve got a question for you. So, the previous owner of my place installed cattle water troughs without a backflow preventer. The float valves are submerged and enter from the bottom of the concrete 500-gallon water trough. I’m wondering if I can just put a check valve under the float valve and be good to go? Or should I go for a double check valve instead? And do double check valves need to be open to atmosphere air? I’m considering switching to an air gap float valve, but I’m worried about freezing during the winter. Any advice?
You have the option of using a check valve underwater. A double check valve will require an atmosphere and may end up blocking ports. However, you can also install it anywhere in the system downstream from the point where it splits to your home, even in a location where it can serve multiple troughs. Another possible solution, depending on the valve itself, would be to extend the outlet port of the current float just above the water level to create an air gap. This method should still function properly, with the tee being based on the water line in the central pipe, which is only about 1/2” above the water line and surrounded by the water volume in the trough.
Can someone point me towards the troughs in relation to the heated structure?
Suggests positioning it far away from any buildings.
How about placing the double check valve or backflow preventer at the water source within the building with the water supply? –