Setting Of Pre-Pressure - Palas VKL 10 Operation Manual

O M VKL 10 /100
PERATION ANUAL

6.3. Setting of Pre-pressure

The pre-pressure is set by turning the knob of the pressure reduction valve and can be seen
on the pressure gauge. With the regulator adjustment completely backed-off the air supply
can be turned on. The adjusting knob can be rotated clockwise to increase the spring load
and the pressure increase observed on the gauge. Minor adjustments after setting changes
can be avoided by always approaching the desired setting from a lower level. When a lower
setting is required, firstly reduce to a lower lever and then increase to the desired setting.
The non rising adjusting knob includes a locking feature; push knob in after setting to lock
and prevent adjustment. To release pull knob out.
IMPORTANT:
In order to avoid overloading of the pressure gauge (zero shifting), the following must be
observed:
If you are not sure whether the pre-pressure control is set to a value smaller than 2.5 bar,
turn the control counterclockwise until it arrests, before starting the VKL. After starting the
VKL, set the desired pre-pressure.
As mentioned under point 6.2, the isokinetic adaptation may be done, within a given range,
by adjusting the prepressure. Figure 6.3 graphically shows the relation between outlet flow
rate and pre-pressure for the delivered outlet nozzles. The outlet flow rate is represented on
the ordinate, and the pre-pressure on the abscissa. To find the correct pre-pressure setting,
proceed as follows:
Take the particle counter flow rate because this is the given, pre-determined outlet flow rate
and find this value on the ordinate.
Starting at this value, draw a line parallel to the abscissa, until the line crosses the curve for
one nozzle. Starting at this point of intersection, draw a line parallel to the ordinate until you
reach the abscissa, and write down the indicated pre-pressure. Install the nozzle belonging
to the cut curve and set to indicated pre-pressure. If the horizontal line does not meet a
curve for a nozzle, order a suitable outlet nozzle with the manufacturer, and indicate the
outlet flow rate.
V V005-06-2020 19
ERSION