DURCHFLUSSBELUEFTER

摘要

The valve for insertion in a water pipe comprises a valve member 5 displaceable to cover or uncover air openings 9 dependant upon water pressure in a flow path 4 between an inlet 2 and an outlet 3. On normal flow the valve member 5 engages a seat 11 to cover the openings 9. If pressure in the flow path is low tending to cause backflow the valve member is sucked against a seat 10 to prevent backflow and vent the outlet.