The unique construction of the vertically sitting fine filter washes out large and fine dirt. Moss, leaves and insects are automatically washed into the drains.
· The WFF filters, attached at a horizontal running sewer pipe, the roof discharge water, which is then supplied to a tank.
WFF 100 - WFF 150
The WFF, that is connected to a horizontal drain, filters the rainwater from the roof which is then led to a cistern.
The rainwater coming from the roof runs into the side of the WFF and is widely spread over the cylinder-shaped filter mesh. The rainwater from the roof is drawn through the vertically placed fine filter there, by exploiting the natural adhesion forces (surface tension), and is led through the outlet to the storage cistern, whilst the dirt is washed into the drain with the remaining water. Over 90% of the rainwater entering the WFF is filtered by this principle.
The full cross-section of the rainwater drainages system remains continuously open in the WFF
There are no reductions in the cross-section of this appliance in which dirt and water can collect. This is especially important with torrential rainfalls where large quantities of water enter. In such cases over 50% of the filtered water is still led to the storage cistern. Excess rainwater is led directly into the drain.
The filter mesh largely cleans itself because practically nothing can remain on the vertical mesh.
Pitched roofs of slate, clay or concrete tiles are most suitable for collecting rainwater. Planted roof areas are less suitable because of the low water-collection efficiency. Non-sealed asbestos cement roofs are unsuitable. They not only cause environmental and health problems but their fibres tend to block the fine filter mesh.
With the help of the blind insert the collection and filtering of the appliance can be stopped. The rainwater from the roof then flows directly into the drain (stopping the rainwater system, winter operation).
Area of application
The effectiveness of the WFF is dependent upon various influences (quantity of rainfall, roof size and pitch, coefficient of discharge etc.). An approximate value for use could be:
WFF100
for roof areas of up to 200m²
WFF150
for roof areas of up to 500m²
1 Housing cover (inspection opening)
2Lifting strap
3Intermediate or closing ring to take cover with Groove for securing cover
4Catch pin to secure the lid
6 filter insert (stainless steel)
7 Rainwater inlet
8Cistern inlet
9 Drain connection
WFF 100
6 filter insert (stainless steel)
7 Rainwater inlet
8Cistern inlet
9 Drain connection
10 Centering pin
11 Reducing piece
Extension pieces are manufactured with PE. The diameter is DN 300 and thus fits both WFF types. The extension piece is required for deeper installations of the vortex fine filter. This raises the inspection opening to ground level.
WFF 150
The closing ring enables paving to be laid. The sunken lid can be easily unlocked by turning.
Soakeaway sieve
There are different methods for soaking away excess and remaining water. The most ideal will depend on the area available, the permeability of the subsoil and the groundwater conditions.
A soakaway sieve can always be inserted in the WFF. It traps large and fine dirt and prevents silting of the soakaway trenches.
The soakaway sieve has to be emptied more often.
Fine filter wall clips (WH 0303)
There are appropriate wall holders for both Vortex fine filters for installation inside rooms.
