Translation of the original operating instructions
Type 327
© 1994 - 2022 SED Flow Control
64
BA220002 Version:
a
Vo
rl
ag
e
: d
o
k360 (
c)
8.
Troubleshooting
Fault
Potential cause
Solution
Valve doesn’t close or close
fully
Control pressure too low (for NO
& DA valves)
Use pressure as specified, see chapter 4.2.3.
Media pressure too high
Do not exceed maximum control pressure,
see chapter 4.2.2.
Control media connection mixed
up
Check control air connection, see chapter
5.2.
Control media not applied
Apply control media
Defect pilot valve
Check pilot valve for function
Foreign matters between weir
and diaphragm
Disassemble valve, remove foreign matters
and check parts for damage. See Chapter
5.3.
Defect diaphragm
Change diaphragm, see chapter 6.2.ff
Defect actuator spring (For NC
valves)
Change actuator, see chapter 5.3.ff
Valve doesn’t open or open
fully
Control pressure too low (for NC
valves)
Use pressure as specified, see chapter 4.2.3.
Control media connection mixed
up
Check control air connection, see chapter
5.2.
Control media not applied
Apply control media
Defect pilot valve
Check pilot valve for function
Wrong assembled diaphragm
Disassemble actuator and assemble
diaphragm correctly. See chapter 6.2.ff
Defect actuator spring (For NO
valves)
Change actuator, see chapter 5.3.ff
Media leakage at diaphragm
flange
Wrong assembled diaphragm
Disassemble actuator and assemble
diaphragm correctly. See chapter 6.2.ff
Tightening torque of screw
connection actuator -diaphragm
too low
Check connection of actuator and valve
body, see chapter 5.3.1.
Defect diaphragm
Change diaphragm, see chapter 6.2.ff
Defect actuator
Change actuator, see chapter 5.3.ff
Defect valve body
Change valve body
Media pressure too high
Do not exceed maximum control pressure,
see chapter 4.2.2.
Operating temperature too high
Do not exceed maximum operating
pressure, see chapter 4.2.1.