Installation - oventrop Cocon QFC Instrucciones De Instalación Y Operación Para El Instalador Especializado

The integrated diaphragm unit (pos. 1a) maintains the differen-
tial pressure "p1" - "p2" at a constant level not only across the
regulating unit (pos. 2) activated by the actuator but also
across the nominal value unit which can be set to a maximum
flow value (pos. 1b).
Even were high differential pressure variations "p1" - "p3" oc-
cur, e.g. if sections of the system are activated or inactivated,
the differential pressure "p1" - "p2" is kept at a constant level.
This way, the valve authority of the "Cocon QFC/QGC" valves
amounts to (a=1). Even during low demand periods with stea-
dy control (e.g. in conjunction with 0-10 V actuators), the valve
authority within the effective valve lift amounts to 100% (a=1).
2.9
Differential pressure p1 - p 3 [psi]
Illus. 7 Flow characteristic line for different presetting
The minimum required differential pressure "p1" - "p3" across
the valve can be obtained from the below chart. As for valves
with integrated flow control, the required minimum differential
pressure changes depending on the nominal setting. The
mathematical interrelationship is considered in the chart.
Nominal setting [GPM]
Illus. 8
As soon as the measured differential pressure is identical with
or higher than the minimum differential pressure "p1" – "p3",
the valve is working within the control range.
.
The maximum flow rate (V) within the control range (2.9 -
58 psi) is set with the help of the handwheel. During low
demand periods, the flow rate is regulated to the required
value by the lift position of the regulating valve.
The pressure independent control valve "Cocon QFC/QGC"
has a linear characteristic line within the active valve lift. This
is advantageous when using actuators which also have a
linear stroke behaviour.
4
Lift position of the Position of the
58
regulating valve handwheel
Item no
1676149
1676150
16761/62/6351
16761/62/6352
16761/62/6353
1676154
1676155
1676156
100
0
Flow volume V [l/h]
Illus. 9 Characteristic line of the valve "Cocon QFC/QGC"
5.2 Markings
Details of the CE marking on the valve handwheel
CE marking
Information on the valve body:
OV Manufacturer
DN Nominal size
PN Nominal pressure
GJL250 / GG25 Valve body material
D in mm outer diameter D of groove connection
5.3 Application
Oventrop pressure independent control valves "Cocon
QFC/QGC" are used for flow control in central heating and
chilled ceiling systems with circulation pump. Room tempera-
ture control can e.g. be carried out by use of room thermost-
ats and actuators.

6 Installation

Before installing the valve, the pipework has to be flushed
thoroughly. Installation is possible in any position (horizontal,
oblique or vertical, in ascending or descending sections; elec-
tric actuators may not be installed vertically downwards – the
installation instructions of the actuator are to be observed). It
is important to note that the direction of flow must conform to
the arrow on the valve body and that the valve must be instal-
led with L = 3 x Ø of straight pipe in the upstream side and
with L = 2 x Ø in the downstream pipe. Any tension which
could be transferred through the pipework must be avoided.
After installation, the handwheel and measuring connection
must be easily accessible.
Once installation is completed, check all installation points for
leaks.
max
.