What is the purpose of a foot valve in a well?
The foot valve is required to be installed at the bottom of the well suction line piping. Similar to the check valve, the foot valve prevents water from flowing back out of the jet pump. This protects against loss of prime in the well piping system.
Does a well point have a foot valve?
Usually a driven point well does not incorporate a foot valve. Rather, since such wells are by definition always shallow, there will be a check valve at or on the pump. I have three options left, a bad foot valve if there is one, leak in piping from well to pump or check valve on suction side is malfunctioning.
Why do you need a foot valve on a well pump?
The weight of the water in the pipe pushes down on the foot valve. Because the foot valve is unidirectional, it doesn’t open in the downward directions. Instead, the pressure from the water closes the valve tightly, which prevents any reverse flow back into the well and from the pump back to the sump.
What happens when a well pump is turned off?
Now, when the pump is turned off, the upward pulling force on the water is removed. As soon as this happens, the Earth’s gravitational pull acts on the water in the pipe, and it tries to flow back into the well with only the foot valve in its way. The entire weight of the water column pushes down onto the foot valve.
What happens if the check valve on a well fails?
The check valve or foot valve prevents the well pressure tank from sending water back down into the well after it has built up with water pressure. If the valve fails, water streams back down the well, and the pressure switch turns the pump on again.
What happens if you lose a foot valve on a jet pump?
Watch out: without a working foot valve, a shallow well jet pump is likely to lose prime and will stop working properly, risking loss of water supply to the building and even damage to the pump itself. Our photo (left) shows the outlet end of a well piping foot valve.
