Well Drain Back Valve

The drain back valve snifter valve opens when the submersible pump stops and pressure in the well piping drops.

Well drain back valve.

The spring loaded drain valve operates hydraulicallyand is designed to close thru the water flow velocity in the pipe. Your water line is always empty when it has drained back. Your water line is always empty when it has drained back. At that point a ball inside the snifter valve moves towards the well piping center away from the outer face or air vent in the valve.

When everything is drained any water in the lines under the house can be ejected at the added outside valve by pushing it out with compressed air from an added drain valve between the well and the inside check valve. The snifter valve allows air into the line to allow the water to drain back to the well. This allows air to enter through a small opening in the snifter valve. The drain back valve in the tee placed in the drop pipe in the well below frost level allows the water to drain back to the well.

The snifter valve allows air into the line to allow the water to drain back to the well. This allows air to enter through a small opening in the valve. No adjustments are necessary. At that point a ball inside the snifter valve moves towards the well piping center away from the outer face or air vent in the valve.

Water begins draining out of the drain back valve. At the same time because the pump has stopped water starts to drain back out of the water piping and out through the orifice of a drain back valve on the well piping not shown where it returns to the well or lake or to another destination depending on the piping system design. The drain back valve in the tee placed in the drop pipe in the well below frost level allows the water to drain back to the well. The drain back valve opens when the submersible pump stops and pressure in the well piping drops.