Georg Fischer DIASTAR SIX Manuel D'utilisation D'origine page 32

5.3 FO-mode / Fail-safe-to-open
In the non-operative state, the valve is open with spring force. When the actuator is pres-
surised with the control medium (top connection), the valve closes. When the control
medium escapes, the valve is opened via spring force.
Pressure ranges and types
Information
• Please consider the pressure­temperature diagrams in the Planning Fundamentals
• Shown pressure ranges depend on the valve body material
Type
Valve body material
Diaphragm
20DN15...50DN40
63DN50
Working pressure
Air connection
Solenoid pilot valve and matching connection thread
3/2-way solenoid valves are used to control single acting actuators (FO). They are mount-
ed either directly to the actuator via a banjo bolt or via a battery mounting plate or valve
cluster, as required.
FO mode of operation with a 3/2-way solenoid valve for top connection
Nominal diameter
20DN15
25DN20
32DN25
40DN32
50DN40
63DN50
32
Ten FO/DA
PVC-U, PVC-C, ABS, PP-H, PP-n,
PVDF, PVDF-HP
Control pres-
EPDM PTFE
sure max.
10 bar 10 bar 5 bar
10 bar 10 bar 5 bar
→← →←
Ten / Sixteen (FO)
G1/8"
G1/8"
G1/8"
G1/8"
G1/4"
G1/4"
Sixteen FO/DA
PVC-C, ABS, PP-H, PP-n
Control pres-
EPDM PTFE
sure max.
10 bar 10 bar 5 bar
10 bar 10 bar 5 bar
→← →←
PVC-U, PVDF, PVDF-HP
Control pres-
EPDM PTFE
sure max.
16 bar 16 bar 5 bar
16 bar 16 bar 5 / 6 bar
→ →