Make sure that the medium flow corresponds
with the direction indicated by the arrow on
the strainer body. Install the strainer with the
filter element suspended downwards.
Ensure that ample space is available to re-
move the filter.
2.3
Additional installation
instructions
Ideally, hand-operated shut-off valves should
be installed both upstream of the strainer
and downstream of the regulator. This allows
the plant to be shut down for cleaning and
maintenance routines, or when it is not oper-
ated for long periods of time. To monitor the
pressures prevailing in the plant, install pres-
sure gauges both upstream and downstream
of the regulator.
3
Operation
3.1
Start-up
Important!
Before starting up or pressurizing the regula-
tor, make sure the orifice (8.5) used to limit
the flow rate is open.
To open the orifice, retract the actuator stem
of the electric actuator using the manual ad-
juster or the electrical control signal. Discon-
nect electric actuators with fail-safe action
from the power supply before disassembling
them in order to open the orifice.
Fill the plant very slowly on start-up.
When carrying out a pressure test on the
section of the plant equipped with a regula-
tor, prevent the diaphragm actuator from be-
ing damaged by the test pressure by using a
test pressure which does not exceed the max-
imum permissible differential pressure
Δ
p of
the diaphragm actuator.
3.2
Set point adjustment
The flow rate can be adjusted both with and
without the electric actuator being attached
to the valve.
3.2.1 Adjustment without actuator
For valve sizes DN 15 to 25, the flow rate
can be set by turning the adjustment screw
(8.3) at the side using a 4 mm hex wrench.
For valve sizes DN 32 to 50, the set point
adjuster (8.2) is used to adjust the flow rate.
1. Turn the adjustment screw (8.3) or set
point adjuster (8.2) clockwise as far as it
will go to close the orifice (8.5) (the ori-
fice of valves in sizes DN 15 to 25 is
closed upon delivery).
2. Determine the number of turns of the
screw or adjuster required to achieve the
desired flow set point from the adjust-
ment diagram on page 7.
(For valve size DN 15, the adjustment
curve that corresponds with the flow coef-
ficient Kvs indicated on the nameplate
must be selected).
3. Based on a closed orifice, adjust the flow
set point by turning the screw or adjuster
counterclockwise. Check the flow rate
and correct it, if necessary.
4. Secure the setting using the lead-sealing
hole or leading screw.
6
EB 3135-1 EN
Operation
