Danfoss PCVQ Operating guide
Instructions
Pilot-controlled PCVQ
DN 100 - DN 250
PN 16 / PN 25
Table of Contents
1 Safety Notes ...................................................... 2
2 Definition of Application ............................ 2
3 Description .......................................................... 3
3.1 Construction ......................................................... 3
3.2 Mode of Operation ........................................... 3
4 Technical Data .................................................. 4
5 Scope of Delivery ............................................. 4
6 Assembly ............................................................. 5
6.1 Prior to Assembly ............................................... 5
6.2 Installation Position,
Installation Place ................................................ 5
6.3 When Installaling observe .............................. 5
6.4 Impulse Tube Installation ................................ 5
6.5 Insulation .............................................................. 5
6.6 Installation Scheme ........................................... 6
6.7 Assembly Drawings, Dimensions ................ 7
7 Start-up ..................................................................9
7.1 Required static Pressure .................................. 9
7.2 Leak and Pressure Test ...................................... 9
7.3 Filling the System ............................................... 9
7.4 Start-up ................................................................... 9
7.5 Putting out of Operation ................................. 9
7.6 Flow Rate Adjustment ....................................... 9
7.7 Flow Adjusting Curves ................................... 11
7.8 Sealing ................................................................. 13
7.9 Adjustement of the Throttle Valves .......... 13
7.10 Function Test ..................................................... 13
8 Trouble Shooting ......................................... 14
9 Replacement of Valve,
Actuator, Trims .............................................. 15
9.1 Dismounting and
Mounting Actuator Valve ............................. 15
9.2 Replacement of Trim Valve VFQ 21 ........... 17
9.3 Dismounting,
Mounting Actuator AVP-F ............................ 18
9.4 Replacement of Trim Valve AVP-F .............. 18
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Instructions Pilot-controlled PCVQ DN 100 - DN 250 (PN 16, PN 25)
1 Safety Notes
2 Definition of
Application
Prior to assembly and
commissioning to avoid injury
of persons and damages of the
devices, it is absolutely
necessary to carefully read and
observe these instructions.
Necessary assembly, start-up, and maintenance
work must be performed only by qualified,
trained and authorized personnel.
Prior to assembly and maintenance work on the
controller, the system must be:
depressurized,
cooled down,
emptied and
cleaned.
Please comply with the instructions of the
system manufacturer or system operator.
The controller is used for flow rate limitation of
water for heating, district heating and cooling
systems.
The admissible medium temperatures depend
on the design and comprise 5 to 150 °C,
5 to 200 °C.
MAINTENANCE
FREE
The technical data on the rating plates determine
the use.
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Instructions Pilot-controlled PCVQ DN 100 - DN 250 (PN 16, PN 25)
Pilot controller AVP-F
Adjusting throttle
T
only by DN150-250
3 Description
3.1 Construction
(Flow Rate)
hrottling valve
3.2 Mode of Operation
The control unit consists of the PCV-VFQ21
valve unit, installed in the main pipe and AVP-F
installed as pilot controllers in the bypass. In the
bypass line, a throttle element is installed in front
of the pilot controller.
The controller keeps the differential pressure
across the main valve flow restrictor on a
constant level and restricts the flow rate to the
adjusted setpoints.
The valve and the pilot valves are pressurebalanced.
The setpoint for the flow rate limitation is
adjusted at the adjusting throttle of the valve
unit.
The valve unit in the main pipe is opening on
rising pressure. The pilot controller in the bypass
line is closing on rising pressure.
Throttling element DE
Valve unit PCV-VFQ 21
Throttling valve
Flow Rate Limitation
If the flow rate reaches the adjusted setpoint, the
differential pressure increases at the adjusting
throttle. This differential pressure acts on the
actuator AVP-F via the impulse tubes and the
valve AVP-F closes. Consequently, the valve of
the valve unit is throttled, too, and the flow rate
is restricted.
4 Technical Data Technical data, see rating plates and the PCV
VI.JA.G3.02
data sheet.
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Instructions Pilot-controlled PCVQ DN 100 - DN 250 (PN 16, PN 25)
5 Scope of Delivery
DN 100, DN 125
Assembly kit valve unit PC V-VFQ 21 Pilot controller DN 25
AVP- F
Throttling element
Cu pipe Ø 6 × 1 × 1500 mm
Cu pipe Ø 10 × 1 × 3000 mm
DN 150, DN 250
Assembly kit valve unit PC V-VFQ 21 Pilot controller DN 40
AVP- F
Throttling element
Cu pipe Ø 6 × 1 × 1500 mm
Cu pipe Ø 10 × 1 × 3000 mm
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Instructions Pilot-controlled PCVQ DN 100 - DN 250 (PN 16, PN 25)
6 Assembly 6.1 Prior to Assembly:
Depressurized system before any
assembly work !
CAUTION!
• Clean pipeline system.
• Install strainer in front of the controller.
• Install shut-off units in front of and behind
the controller.
6.2 Installation Position, Installation Place
• Installation is only permitted in horizontal
pipelines with the actuators hanging in a
downward position.
• The controller may be installed in the supply
as well as in the return line.
6.3 When installing:
• Observe direction of flow.
• Design with welded ends:
6.4 Impulse Tube Installation
See installation scheme, section 6.6.
For CU pipes Ø 10 × 1, insert sockets 1 on both
sides.
1
Care for correct position of the cutting rings 2.
2
pin only
weld
do NOT
weld
• Loads on the valve body and the throttle
element by the pipes are not permitted.
6.5 Insulation
The diaphragm actuators must not be insulated
when insulating system parts.
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Instructions Pilot-controlled PCVQ DN 100 - DN 250 (PN 16, PN 25)
Valve unit PCV - VFQ 21
Pilot controller AVP-F
6 Assembly
6.6 Installation Scheme
Installation in the Return Line
Valve unit PCV - VFQ 21
Installation in the Supply Line
Throttling valve
Throttling
element
Throttling valve
(only by DN 150 - 250)
Bypass controller
PCVQ
Throttling valve
Throttling
element
Throttling valve
(only by DN 150 - 250)
Bypass controller
PCVQ
Pilotregler AVP-F
lay impulse tube during mounting
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