Festo VZQA-C-M22U Serie Manual De Instrucciones página 4

Proportional media valve
VZQA-C-M22U-...
(en) Operating instructions
Original: de
Proportional media valve VZQA-C-M22U
1 Design
3
2
1
4
1
Female threaded connection; feed
or transfer (version depending on
type Fig. 5; G½ or NPT½)
2
Valve housing
Fig. 1
The proportional media valve VZQA-C has an easy-to-clean cylindrical housing
Fig. 1, 2 ). Connections for connecting media-carrying lines are located on
(
Fig. 1, 1 ).
both sides (
In the middle of the housing is the pilot air port, via which the valve is pneumatic-
Fig. 1, 3 ).
ally actuated (
Inside is a cartridge with a tubular pinch valve sleeve. This can encase solid
particles in media streams. It also allows the valve to be tightly shut off for existing
solid particles. A minor leak rate cannot be excluded, however, as this depends on
the size and concentration of the solid particles.
The proportional media valve is available in various designs. This document
describes product versions with the following type code:
Key features Type
codes
Type code VZQ
Series A-
Product design C-
Valve function M22U-
Nominal diameter DN 15-
Connection type 1 G
T
Connection type 2 G-
T-
Housing material V4
Material for housing cover V4
Material for shut-off ele- N-
ment
Pressure range medium 4
Fig. 2: Type code VZQA-C-M22U-... (e.g. VZQA-C-M22U-15-GG-V4V4N-4)
Festo AG & Co. KG
Postfach
D-73726 Esslingen
++49/711/347-0
www.festo.com
758 453
1109NH
. . . . . . . . . . . . . . . . . . . . . . . . . . .
3
Pilot air port 12; (GÁ, max.
permissible thread length 5 mm)
4
Inside: Cartridge with tubular
pinch valve sleeve
Description
Proportional media valve
Series A - pneumatically actuated
Easy to clean design (Clean design)
2/2-way valve, normally open
DN15
Connection 1 : G-female thread
Connection 1 : NPT-female thread
Connection 2: G-female thread
Connection 2: NPT-female thread
Stainless steel
Stainless steel
Nitrile rubber (NBR)
0 ... 4 bar
2 Function
The proportional media valve is a pneumatically actuated 2/2-way valve. The valve
is open when at rest (normally open - NO).
The pinch valve sleeve inside the valve is compressed
by applying the pilot pressure to the pilot air port
Fig. 1, 3 ). When there is a sufficiently high
(
differential pressure (
and section 6) the valve is closed. If the pilot port is
exhausted again, the pinch valve sleeve re-opens
with the help of its own resetting force and the
medium pressure.
Free passage in an open state ensures minimal flow resistance and prevents the
valve from clogging or blocking.
The supply of pilot pressure must be controlled by an external valve, which is to be
installed in the pilot line.
3 Application
Valves in the VZQA-C-M22U-... series are exclusively intended for controlling
gaseous, liquid, past-like, powdery and solid media (granulates), as well as mix-
tures of substances in piping systems with low to medium switching frequency
(permissible operating and pilot media
ing frequencies can lead to higher maintenance expenditure, as the valve must be
checked for leaks more frequently due to the higher load. If any leakage is detec-
English
ted, the cartridge (
Operating media and pilot media are only separated from one another in the pro-
portional media valve by the pinch valve sleeve integrated in the cartridge. When
using the product it should be noted that a damaged cartridge has the following
consequences:
1
– Hermetic separation between the operating medium and pilot medium is no
longer guaranteed.
– Operating medium enters the control circuit, where it escapes (e.g. on a
silencer).
– Pilot medium enters the operating medium circuit. The pressure in the operating
medium circuit increases accordingly (pressure compensation of both circuits).
– The proportional media valve no longer closes properly.
The proportional media valve should only be used in systems in which a damaged
or leaking cartridge cannot result in a hazard to personnel or damage to property.
The media circuit must designed for the set pilot pressure.
The designer of the system and the system operator are responsible for the suit-
ability of the product in combination with the respective system, as well as for the
resistance of the material used for the cartridge with regard to the operating
medium applied. Corresponding investigations are usually required to evaluate the
suitability of the system. The risks associated with a leaking cartridge and the
corresponding consequences must be taken into account when planning the
system!
Operating media should only be used if the material used for the cartridge and
cover are resistant to it and if it does not react when mixed with the pilot medium
(media resistance
– The product may only be used in its original state without unauthorised modific-
ations. Only the mounting and repair options described are permitted.
– Comply with the permissible limit values and specifications (
Technical data).
– Only use the product if it is in perfect technical condition.
– Only use neutral operating and pilot media in accordance with the specifications
( section 12, Technical data). Please contact our customer support depart-
ment before using any other operating media.
– All applicable national and international regulations must be complied with.
– Switching the valve too quickly will decrease the service life of the integrated
cartridge. Operate the pilot pressure with a maximum standard nominal flow
rate of 40 l /min or a control valve with a maximum nominal diameter of 1.0 mm.
Recommendation: Use pressure limiters to avoid accidentally exceeding the oper-
ating and pilot pressure.
4 Transport and storage
Ensure storage conditions as follows:
– Short storage periods in cool, dry, shaded and corrosion-protected locations.
5 Installation
Warning
Risk of crushing inside the valve!
If the valve is charged with pilot pressure, any fingers in the opening or inside the
valve will be crushed.
• Do not reach into the opening of the valve.
section 12, Technical data
section 12, Technical data). High switch-
Fig. 1, 4 ) must be replaced.
www.festo.com).
Fig. 3
section 12,