AWG I Operating manual I Fittings I
Inductors FD Z2 and Z4
USE
32 / 40
ENGLISH
M1088B10 I Rev. 01-02/20
Pressure loss in the inductor
The suction capability of the inductors is fundamentally based on a
considerable pressure loss.
This pressure loss in the inductor depends on the counter pressure at
the inductor outlet and is calculated as the hose friction plus the differ-
ence in height between the inductor and the foam nozzle.
At an optimal counter pressure of approx. 2 to 3 bar max., the pressure
loss amounts to approx. 45
% to 50
% depending on the chosen suc-
tion rate. If the counter pressure is higher, the pressure loss in the in-
ductor decreases to approx. 30
% to 35
%.
Use of foam nozzles in heights up to approx. 30
m
At high inlet pressures of approx. 12 to 16 bar, the inductor
is capable of aspirating even with height differences of up to
30
m.
Inductor inlet pressure
Optimum pressure ranges
Inductor inlet
Inductor outlet
Low expansion foam nozzle
Medium expansion foam nozzle
8 bar – 9.5 bar
6 bar – 7 bar
5 bar – 6 bar
3 bar – 4 bar
The pressure ratio between inductor inlet and outlet varies depending
on the chosen suction rate.
Suction height of the foam agent
If the suction height of the foam agent is greater than approx. 2
m, the
rates set at the metering valve are sometimes significantly undercut.
This applies in particular to rates above 3
%.
Notes on the admixing rate
The specified admixing rates are applicable for synclic foam agents or
foam concentrates. The scale on the setting sleeve is calibrated for
synthetic multi-grade foam agents.
Especially in the range of 0.1 to 0.5 %, the aspirated volume depends
strongly on the viscosity of the foam agent. In view of this, the EN
16712-1 standard allows, for up to 1%, a large rate tolerance of 50%.
Water is for example significantly more aspirated.
The scale on the setting sleeve thus only indicates a guide value.
Note
In position "0", a minimum residual quantity can be aspirated.
