Festo VNIA-01-ZR Series Brief Description page 20

2.2 Fitting pneumatic components
Valve terminal type VNIA−...
Please note
For valve terminals with S valves (valves which must be
piloted with external auxiliary pilot air), use only con
nection 14 to feed the auxiliary pilot air to an end plate
and to both end plates when using the NZV... adapter
block.
The pilot exhaust is individually vented for these valves in
the standard design. If you want to vent the pilot exhaust
in common ducts or with silencers via connection 12, you
must turn the seals between the valve terminals and the
connection blocks (see illustration):
20 Festo VNIA−01/02−ZR.. 0403a English