Festo VTSA-44-ASI Series, Manual, Page: 44 / 220

1. Summary of components
1-28
Festo P.BE-VTSA-44-EN en 1101f
Fig. 1/7: Electrical soft-start valve
The optimum pressure build-up required by the application
for each pressure zone is configured directly on the valve
terminal by setting the switchover pressure and filling time.
The VTSA/VTSA-F valve terminal can either be operated with
an internal pilot air supply via the soft-start valve or with an
internal or external pilot air supply via the different end
plates. The type of pilot air supply is determined by the seal
of the soft-start valve.
The soft-start valve is actuated electrically independently by
the multi-pin/fieldbus connection via a 4-pin plug (in accord-
ance with ISO 15407-1) or separately via an optional M12
adapter.
Switch-on takes place in two stages:
– First the working pressure provided for duct (1) gradually
increases. The speed can be adjusted using a flow control
screw.
– Once the working pressure in duct (1) reaches a previously
set value, the soft-start valve switches the full operating
pressure at duct (1) of the valve terminal.
When the valve terminal is supplied with internal pilot air via
the soft-start valve, the full operating pressure is always
present at duct (14). This pressure causes the valves on the
valve terminal to immediately move to the required switching