Encyclopedia & FAQ's

DIY Frequently Asked Questions / Check Valve


  • DIY Frequently Asked Questions / Check Valve')"> Operates automatically, permitting flow in one direction only.
  • Sometimes combined with a throttling or shut-off valve. Some communities require a check valve in cold water lines between the water heater and meter.
  • Used to prevent water pumped to an overhead tank from flowing back when the pump stops.
  • Some check valves are designed for use with vertical pipes only. Therefore, it will not work if installed upside down. The closing deviceóa disk, ball or clapperófalls shut by gravity when installed vertically.
  • Another variety is the Swing-Type check valve, which is a small, smooth swing-type gate located in the center of the valve. As water is pumped through the flow side of the valve, a gate swings open to allow water to pass. If water attempts to back up through the valve, the gate is forced shut against the pressure side of the valve.