The Funke non return valve is designed for the drainage of faeces-free wastewater, and is available as a single flap (type-1) or double flap (type-2) non return valve.
The non return valve can only be used to prevent backflow at drainage points below the backflow level. All drainage points above this level must bypass the non return valve and flow freely into the drainage system, with separate sewer system.
The advantages in practice:
- available in nominal diameters of DN/OD 110, and 160
- screw cap
- with emergency locking mechanism