Festo VZXA M Series, Instructions & Operating

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6 Product overview
6.1 Design
1
2
3
4
5
6
7
8
9
5
1
Position indicator (
è
Fig. 6)
2
Pneumatic connection (2)
3
Actuator housing
4
Leakage hole
5
Pipe connection;
Feed or forwarding (corresponding
to flow direction)
6
Arrow for direction of flow
7
Valve housing
8
Actuator interface / angle seat
valve with spanner flat
9
Pneumatic connection (4)
Fig. 3
6.2 Product variants and type code
Fig. 4 explains selected product characteristics that are necessary
to understand the instructions.
Description of the complete type code:
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www.festo.com/catalogue
Characteristic Value Description
Type VZXA Angle seat valve
Medium flow A Over valve seat - closing in the direction of medium
flow (for gaseous media)
B Under valve seat - closing against the direction of me­
dia flow (for gaseous and fluid media)
Connection type TS6, TS7, TS13 Line connection and connection standard
è
Fig. 10
Temperature
of medium M2 –10…+180 °C
M3 –30…+200 °C
Medium pressure 4 to 30 0…4 bar to 0…30 bar
Valve housing material V13 Stainless steel 1.4409
V14 Stainless steel ASTM A351-CF3M
Seat seal material TP PTFE modified
T PTFE
Actuator M Diaphragm actuator
Actuator size 90 90 mm
Control function Closed via spring force, NC
S Opened via spring force, NO
PR Closed via reduced spring force, NC
Fig. 4
6.3 Function
The angle seat valve VZXA-...-M is an externally controlled 2/2-directional control
valve with diaphragm actuator. The valve seat is slanted around 40° toward the
medium flow.
To close the valve, the valve actuator using the actuator rod presses the valve disc
into the valve seat in a force fit.
The supply of the operating medium is controlled by an external valve (usually
electrically controlled) that must be additionally integrated into the supply line for
the actuator.
The actuator can be rotated 360° on the valve housing.
Flow over valve seat
The valve is closed by spring force with the medium flow.
– Medium pressure supports valve closing.
– The valve is opened with operating pressure.
– Only suitable for gaseous media, because use of incompressible media causes
pressure surges in the piping.
Flow under valve seat
The valve is closed by spring force or with operating pressure against the medium
flow.
– Medium pressure supports the valve opening.
– In certain constructions, medium pressure that is too high or operating pressure
that is too low can lead to the valve not completely closing.
Control function
Single-acting
Closed via spring force or through reduced
spring force (normally closed - NC) Opened via spring force (normally open - NO)
Fig. 5
Position indicator
The pneumatic position indication shows the position of the actuator rod.
Indicator cylinder above Indicator cylinder below
Actuator rod retracted, valve opened Actuator rod extended, valve closed
Fig. 6
7 Transport and storage
When shipping used products: comply with all legal requirements for handling
hazardous substances and transporting dangerous goods.
For return to Festo
è
Chap. 2.
Store the product in a cool, dry, UV- and corrosion-protected environment.
Ensure that storage times are kept to a minimum.