VZXA-...-C.../W...-...-M-...-V4
Angle seat valve with diaphragm actuatorb
Festo SE & Co. KG
Ruiter Straße 82
73734 Esslingen
Deutschland
+49 711 347-0
www.festo.com
Operating instructions
8155473
2021-07
[8155475]
Translation of the original instructions
© 2021 all rights reserved to Festo SE & Co. KG
1
About this document
1.1
Applicable Documents
All available documents for the product
2
Safety
2.1
General safety instructions
–
Only use the product in original status without unauthorised modifications.
–
Only use the product if it is in perfect technical condition.
–
Use the valve only in the flow direction indicated.
–
Take into consideration the ambient conditions at the location of use.
Media
–
Use only media in accordance with the specifications
–
Use only media that will not cause dangerous reactions if mixed.
–
Do not operate the product with chemically unstable gases, abrasive media or
solid materials.
–
When using saturated water vapour: take vapour pressure into account when
designing the valve.
Drive
–
Do not open the drive (pressure in the drive or spring under tension).
–
Avoid mechanical stresses on the valve. Do not use the drive as a lever.
Return to Festo
Hazardous substances can endanger the health and safety of personnel and
cause damage to the environment. To prevent hazards, the product should only be
returned upon explicit request by Festo.
–
Consult your regional Festo contact.
–
Complete the declaration of contamination and attach it to the outside of the
packaging.
–
Comply with all legal requirements for the handling of hazardous substances
and the transport of dangerous goods.
2.2
Intended use
The angle seat valve VZXA-...-M is intended to shut-off gaseous or liquid media in
piping systems.
–
Use only the product variant VZXA-B-...-M (media flow under valve seat) for
control of liquid media.
2.3
Training of qualified personnel
Work on the product may only be carried out by qualified personnel who can eval-
uate the work and detect dangers. Personnel must have the relevant mechanical
training. The qualified personnel have knowledge and experience in pneumatics.
3
Additional information
–
Contact the regional Festo contact if you have technical problems
–
Accessories and spare parts
4
Product overview
4.1
Structure
4.1.1
Product design
5
6
7
1
8
3
2
5
9
4
Fig.1
1
Pneumatic port (4)
2
Drive/angle seat valve interface
with spanner flat
3
Leakage hole
4
Valve housing
5
Pipe connection; feed or for-
warding (depending on flow
direction)
6
Position indicator
7
Pneumatic port (2)
8
Drive housing
9
Arrow for flow direction
Position indicator
The pneumatic position indicator shows the position of the actuator stem.
Indicator cylinder above
Indicator cylinder below
Actuator stem retracted, valve opened
Actuator stem extended, valve closed
Tab. 1: Position indicator
4.2
Function
The angle seat valve VZXA-...-M is an externally controlled 2/2 directional control
valve with diaphragm actuator. The valve seat is slanted approx. 40° toward the
media flow. To close the valve, the valve actuator using the actuator stem 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 actuated) that must also be integrated into the supply cable for the
drive.
The actuator can be rotated 360° around the valve body.
Flow over valve seat
The valve is closed by spring force with the medium flow.
–
Media pressure assists the closing of the valve.
–
The valve is opened by 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 by operating pressure against the media
flow.
–
Media pressure assists the opening of the valve.
–
In some designs media pressure that is too high or operating pressure that is
too low can result in the valve not closing completely.
Control function
Single-acting
Closed by spring force or by reduced spring force
(normally closed - NC)
Opened by spring force (normally open- NO)
Tab. 2: Control function
5
Transport and storage
•
For delivery of used products: Comply with all legal requirements for the
handling of hazardous substances and the transport of dangerous goods. For
returns to Festo
•
Store the product in a cool, dry, UV-protected and corrosion-protected envi-
ronment. Ensure that storage times are kept to a minimum.
6
Assembly and installation
Requirements
–
The piping is unpressurised and there is no medium flowing through it.
–
The pipe ends are mounted.
–
Connecting cables and fittings are clean.
