Technical Data; Performance Data; Construction And Function - oventrop Cocon QTZ Instructions D'installation Et D'utilisation

Attention:
• Please protect against external forces (e.g. impacts,
vibrations etc.).
• External components such as handwheels, pressure
test points, actuators must not be misused for the
absorption of external forces, e.g. as connection point
for lever tools etc.
• Suitable means of transport and fitting devices have to
be used.

4. Technical data

4.1. Performance data

Max. working temperature: 120 °C
Min. working temperature: -10 °C
Max. working pressure: 16 bar (1600 kPa)
Fluid: Water or mixtures of water and
ethylene/propylene (max. 50 %),
ph-value 6.5-10
Control range:
Control range [l/h]
DN (min.-max.)
- see illustr. 7 -
10
30 - 210
10 90 - 450
15 30 - 210
15 90 - 450
15 150 -1050
20 150 -1050
20 180 -1300
25 300 -2000
32 600 -3600
Data for actuator connection:
Connection thread: M30 x 1.5
Piston stroke: 2.8 mm
(DN 10/15/20: 30-1050 l/h)
3.5 mm
(DN 20: 180-1300 l/h)
4 mm
(DN 25 and DN 32)
Closing dimension: 11.8 mm
Closing pressure (actuator):90 - 150 N
DANGER
Suitable measures (e.g. safety valves) have to be taken
so that the maximum working pressures and maximum
and minimum working temperatures are not exceeded or
undercut.
4.2. Materials
Body made of de-zincification resistant brass, seals made of
EPDM or PTFE, valve stem made of stainless steel.

5. Construction and function

5.1. Survey / Functional description
The Oventrop combined control and regulating valve "Cocon
QTZ" is a flow regulator which also maintains the differential
pressure at a constant value with the help of the regulating
valve activated by the actuator. The room temperature can be
controlled with the help of actuators and room thermostats.
The flow-meter "OV-DMC 2" can be connected to the pressure
test points (model "Cocon QTZ" with pressure test points).
This will confirm if the valve is working within the control range.
The pump setting can be optimised by measuring the differ-
ential pressure (illustr. 5.4).
6
Differential pressure p - p
1 3
(min.-max.)
- see illustr. 5.1 -
0,2 bar-4 bar
(20 kPa-400 kPa)
0,15 bar-4 bar
(15 kPa-400 kPa)
For this purpose, the pump head is reduced until the hydrauli-
cally underprivileged valves are just working within the control
range.
As the measured differential pressure ist not identical with the
minimum differential pressure (p1-p3) for valve design, the fol-
lowing charts have to be applied.
With a flow-meter (e.g. "OV-DMC 2") (illustr. 5.4) connected,
the differential pressure is measured across the flow unit (pos.
3, illustr. 5.1/5.2). To do so, the regulating valve must be fully
opened (unscrew protection cap or set actuator to open posi-
tion). As soon as the measured differential pressure has
reached or exceeded the differential pressure ∆p
shown in the chart, the valve is working within the control
range.
Nominal value settings [l/h]
Nominal value settings [l/h]
The max. flow rate can be chosen with the help of the protect-
ed presetting at the handwheel. Operation during low demand
periods is controlled via the actuator or the room thermostat.
With the help of the integrated diaphragm unit (pos. 1a, illustr.
5.1/5.2), the combined control and regulating valve "Cocon
QTZ" maintains the differential pressure "p2"-"p3" at a con-
stant level not only across the regulating unit activated by an
actuator (pos. 2, illustr. 5.1/5.2) but also across the nominal
value unit which can be set to a maximum flow value (pos.
1b, illustr. 5.1/5.2).
Even where high differential pressure variations "p1"-"p3" oc-
cur, e.g. during part load conditions, the differential pressure
"p2"-"p3" is kept at a constant level. This way the valve au-
thority of the "Cocon QTZ" valves amounts to 100 % (a = 1).
Even during part load conditions with steady control (e.g. in
combination with 0 - 10 V actuators), the valve authority of the
"Cocon QTZ" valves amounts to 100 % (a = 1) within the ef-
fective valve lift.
The regulating unit (pos. 2, illustr. 5.1/5.2) has an almost
linear characteristic line (illustr. 5.3).
1 Flow control unit
1a Diaphragm unit
1b Nominal value unit
2 Regulating unit
Illustr. 5.1 Construction "Cocon QTZ"
which is
M
2
1a
1b