Samson 3374 Series - Direction of Action

16-4 EB 8331-4 EN
Annex A (conguration instructions)
The input signal must be ≥0.5V or ≥1mA to be able to detect a malfunction.
16.3 Direction of action
Î RefertoFig.16-3.
− Increasing/increasing (c42 = >>):
The actuator stem retracts as the input signal increases.
− Increasing/decreasing (c42 = <>):
The actuator stem extends as the input signal increases.
Actuator stem extended
− With globe valves: Valve closed
− With three-way mixing valves: Port A àABopen,BàABclosed
− Withthree-waydivertingvalves:PortABàAclosed,ABàBopen
Actuator stem retracted
− With globe valves: Valve open
− With three-way mixing valves: Port A àABclosed,BàABopen
− Withthree-waydivertingvalves:PortABàAopen,ABàBclosed
A
B
AB
AB
A
B
A
AB
B
AB
A
B
Mixing valve for mixing service
Diverting valve for mixing service
For diverting service
For diverting service
Flow pipe
Flow pipe
Flow pipe
Flow pipe
Returnowpipe
Returnowpipe
Returnowpipe
Returnowpipe
Fig.16-3: Operating principle of three-way mixing and diverting valves
Note