5
4.
Technical data
As a general rule, the choice of a PURAIN rainwater filter is made based on the diameter of the
rainwater collecting pipe stipulated by the building architect or water engineer e.g. DN150 (160mm)
= PR-150-S.
If the diameter of the planned collecting pipe is not known, then you can refer to the following table.
It gives an overview of the dimensions of these rain water connection pipes, as per DIN 1986, with
measured rainfall yield indicator of r = 300 l/s ha and a slope of 1.5%. The discharge coefficient
indicates by what factor the amount of rain discharged may be reduced, due to the type of roof used
(considering water fall, velocity, evaporation, overflow, etc).
•
Discharge coefficient 1 = theoretical value
•
Discharge coefficient 0.8 = inclined roof
•
Discharge coefficient 0,5 = extensively grassed roof
Flow rate with 1,5 %
slope DIN 1986
Discharge
coefficient = 1,0
Discharge
coefficient = 0,8
[average used]
Discharge
coefficient = 0,5
DN100
5,7 [l/s]
190 m²
238 m²
380 m²
DN150
16,9 [l/s]
564 m²
705 m²
1.128 m²
DN200
36,3 [l/s]
1.210 m²
1.513 m²
2.420 m²
DN300
106,1 [l/s]
3.537 m²
4.422 m²
7.074 m²
DN400
226,8 [l/s]
7.560 m²
9.450 m²
15.120 m²
