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Festo — VTSA-F-CB — 2021-06a
Installation
1.
7.1.1.2
Pressure rise in the overall supply
Supply component
Pressure rise in the
overall supply
Movement of the
actuator
Pressure rise in the
pilot air
Right-hand end plate
fast
fast
Supply plate
Soft start valve with provision of
pilot air
slow
Soft start valve without provi-
sion of pilot air
–
Pilot air switching valve
–
fast
Tab. 35: Pressure rise in the overall supply
The pressure increase of the total supply and the movement of the actuator depend on the supplying
component.
The pressure rise of the pilot air in duct (14) is independent of the supply component. Depending on
the valve function, the working valves move immediately to the set switching position.
7.1.1.3
Preventing back pressure
When exhausting large-volume actuators or if the exhaust performance is too low, back pressure may
build up in the valve terminal's exhaust ducts. This back pressure can lead to pneumatic actuation of
other valves, especially with unswitched 3/2-way valves that are normally closed.
Optimise pressurisation and exhaust performance of the valve terminal, e.g. with the following
measures:
–
larger tubing diameters
–
additional pressure feed via pneumatic supply plates
–
Exhausting via pneumatic supply plates with silencer or exhaust plate
–
Separate exhaust air ducts with pressure zones
11.2.1 Converting to Multiple Pressure
2. Install check valves in common exhaust lines
7.1.2.2 Common pneumatic lines.
7.1.1.4
Check prerequisites for vacuum or low pressure operation (valves with Identcode VV)
Before connecting valves with Identcode VV, check the requirements for vacuum or low-pressure
operation:
–
Supply operating pressure for the pneumatic springs at port (1).
–
Supply vacuum to port (5) and operating pressure to port (3) or vacuum to port (3) and operating
pressure to port (5).
–
To enable the ejector pulse during vacuum operation, establish a connection between the suction
line and the pressure supply line with a T-piece.
7.1.2
Connecting pneumatic lines
Observe the following points when connecting the pneumatic lines:
–
For external pilot air supply, you only need to supply the pilot air at port (14).
–
If the internal pilot air supply (duct 14) is via a soft start valve or pilot air switching valve, do not
connect an additional pilot air supply.