Festo VTSA-44-MP Series Manual page 129

4. Commissioning
Festo P.BE-VTSA-44-EN en 1101f
The pilot air must be applied immediately after it is switched
on at the minimum pressure specified in Appendix A, Tab. A/6
for the relevant valves. Otherwise it is not ensured that the
valve will switch directly (see diagram).
If the pressure is less than the minimum specified, there may
be a delay before the valve is switched, in spite of an electric
signal being present. The gradual pressure build-up of the
overall supply does not affect the actuator in that case. The
actuator would react suddenly (e.g. a cylinder would extend
or retract suddenly, depending on the valve function).
82/84
14
1
1
Externally supplied pilot air, branched in front of the
on-off valve
2
Soft-start valve of complete supply
Fig. 4/1: Example of valve-cylinder combination with
gradual pressure build-up of the overall supply
4 2
1
12/14
5 3
2
12/14
1
12
3
2
4-5