8.2
pneumatic installation of
feedback head Type 8685
The feedback head does not require a pilot air supply.
A description of the pneumatic installation of the actuator is
included in the valve operating instructions.
8.3
pneumatic installation of control
head Type 8686
Danger!
risk of injury from high pressure in the equipment/device.
▶ Before working on equipment or device, switch off the pressure
and deaerate/drain lines.
procedure:
→
Connect the control medium to the pilot air port (1)
(6 – 7 bar; instrument air, free of oil, water and dust).
→
Mount the exhaust air line or a silencer on the exhaust air port (3)
(see "Fig. 13: Pneumatic connection Type 8686").
20
English
Type 8685 / 8686
Pneumaticinstallation
Important information for the problem-free functioning of
the device:
▶ The installation must not cause back pressure to build up.
▶ To make the connection, select a hose with sufficient cross
section.
▶ The exhaust air line must be designed in such a way that
no water or other liquid can get into the device through the
exhaust air connection (3).
Fig. 13: Pneumatic connection Type 8686
Caution (exhaust air concept): In compliance with degree
of protection IP65 / IP67, an exhaust air line must be
installed in the dry area.
always maintain an applied control pressure of at least
0.5 – 1 bar above the pressure which is required to move the
actuator to its end position.
Exhaust air port
Label: 3
Pilot air port
Label: 1