Festo VZXA-***-M Series, Instructions For Use

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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. 3
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. 4
6 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.
7 Mounting and installation
Note
Mounting and installation should only be carried out by qualified personnel.
7.1 Installing the angle seat valve
Prerequisites
– The piping system is unpressurised and no medium flows in it
– Lines are clean
– The line ends are mounted
Clean valve
Remove all transport packaging. The material used in the packaging has been
specifically chosen for its recyclability (exception: oil-impregnated paper =
residual waste).
Traces of residual grease may be evident on the product due to the production
process used.
Clean the valve immediately before installation.
Warning
Risk of injury due to slipping or falling objects!
The angle seat valve can weigh up to 11.5 kg, depending on the product version.
Body parts can be crushed. In overhead installations, the result can be serious
head injuries.
Angle seat valve with appropriate means of securing against falling or
slipping.
1. Bring the angle seat valve into the mounting position.
– Observe the flow direction. The permitted direction of flow is marked by an
arrow on the valve housing.
2. Connect the piping on the valve housing.
– Max. tightening torque
è
Fig. 5.
3. Connect the line of the operating medium.
– Pneumatic connection (2): operating medium
– Pneumatic connection (4): exhaust port
4. For single-acting actuators: mount the silencer in the exhaust port or use
a tubing connection for guided exhaust air.
Connection size [”] 1 1¼ 1½ 2 2½
Max. tightening torque
pipe connection [Nm] 350 450 540 620 750
Fig. 5
8 Commissioning
Warning
Risk of injury from manipulation in the area of the angle seat valve!
Limbs can be cut or severed.
Place only the fully mounted angle seat valve in operation.
Note
Commissioning should only be carried out by qualified personnel.
Prerequisites
– The valve is fully mounted and connected
Checking operating conditions
Observe operating conditions and limits
è
Technical data and product labelling.
Check connection points for tightness.
Check compatibility of the devices in the system for maximum pressure
(consider pressure peaks). If necessary, adjust the application parameters.
Placing valve in operation
1. Supply medium.
2. Slowly apply operating pressure to the valve. The operating pressure required
for reliable switching of the valve depends on the medium pressure
è
Fig. 10 to Fig. 15.
3. Function and direction control of the individual pneumatic actuators.
9 Operation
Danger
Risk of injury from touching hot surfaces!
Valve and actuator can become hot at high temperature of medium. Severe
burns are possible.
Do not touch the angle seat valve during operation or immediately afterward.
Comply with operating conditions.
Comply with maintenance conditions
è
Chap. 11.
After longer idle times:
Actuate the valve several times and check for correct function.
10 Malfunctions
Malfunction Possible cause Remedy
Valve does not
close or closes
too slowly VZXA-B: medium pressure is too high
or operating pressure too low Creating necessary differential
pressure
è
Technical data.
Adjust operating pressure.
Too many contaminants, or contamin­
ants that are too large, in the medium Comply with operating condi­
tions.
Valve does not
open or opens
too slowly VZXA-A: operating pressure is too low
or medium pressure too high Adjust operating pressure or
medium pressure.
VZXA-B: operating pressure too low Adjust operating pressure.
Medium leaking
from a leakage
hole Seal cartridge defective Replace seal cartridge
è
Spare parts documentation.
Medium will not
let itself be
shut off Seat seal defective Replace seat seal
è
Spare parts documentation.
Fig. 6