oventrop Cocon QTZ Technical Information

Application:
The pressure independent control valve "Cocon QTZ" with automa-
tic flow control is a valve combination consisting of a flow regulator
and a regulating valve. The nominal value of the flow regulator can
be set with the help of an easily accessible handwheel. The pressure
independent valve can be equipped with an actuator, a temperature
controller or a manual head (connection thread M 30 x 1.5).
The pressure independent control valve "Cocon QTZ" is designed
to be installed in heating and cooling systems (e.g. central or under-
floor heating systems, fan coil units, chilled ceilings, fan convectors
etc.) with closed circuits for automatic flow control (hydronic
balancing). It can also be used for the control of another variable
(e.g. room temperature) by modifying the flow rate with the help of
actuators, thermostats or temperature controllers.
Technical data:
Performance data
Max. operating temperature: +120°C
Min. operating temperature: -10°C
Max. operating pressure: 16 bar (1600 kPa)
Fluid: Water or mixtures of water and
ethylene/propylene-glycol
(max. 50 ), ph-value 6.5-10
Max. closing pressure: 16 bar (1600 kPa)
in the direction of flow
Control range:
Control range [l/h]
DN
(min.-max.)
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: M 30 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 und DN 32)
Closing dimension: 11.8 mm
Closing pressure (actuator): 90 - 150 N
Materials:
Body made of dezincification resistant brass, seals made of
EPDM or PTFE, valve stem made of stainless steel.
Function:
The required flow rate is set at the handwheel (see page 3 at the
bottom). The nominal setting can be secured by engaging the
handwheel and by inserting the locking ring which is lead sealable.
During low demand periods, regulation can be carried out with the
help of an actuator or a temperature controller which can be
screwed onto the valve.
2015 Oventrop
Differential pressure p -p
1 3
(min.-max.)
0.2 bar-4 bar
(20 kPa-400 kPa)
0.15 bar-4 bar
(15 kPa-400 kPa)
Pressure independent control valve
"Cocon QTZ"
Legend:
1 Flow control unit
1a Diaphragm unit
1b Nominal value unit
2 Control unit
p1 p2
1a
p1-p3
The illustrated section of the pressure independent control valve
"Cocon QTZ" shows three pressure ranges:
"p1" is the inlet pressure and "p3" the outlet pressure of the valve.
"p2" is the pressure actuating the integrated diaphragm unit (pos.
1 a) which maintains the differential pressure "p2" – "p3" at a con-
stant level via the regulating unit (pos. 2) which is activated
through the actuator and via the nominal value unit (pos. 1 b)
which can be set to a maximum flow rate.
Even where high differential pressure variations "p1" – "p3" occur,
e.g. if sections of the system are activated or inactivated, the
differential pressure "p2" – "p3" is kept at a constant level. This
way the valve authorities of 100
during low demand periods with steady control (e.g. in combina-
tion with 0-10 V actuators), the valve authority of the "Cocon
QTZ" valve within the effective valve lift amounts to 100
"Cocon QTZ"
Technical information
2
1a
1b
p3
1b
2
∆p
M
p2-p3 = constant
are maintained (a = 1). Even
(a = 1).
1