12
8. Malfunction / defects and fault clearance
Malfunc-
tion
Possible reason
Fault clearance
Leakage
in the pas-
sageway
• The allowed valve operating
limits (pressure / tempera-
ture) have been exceeded.
• Damage of the sleeve or
plug resp. ball surface
caused by foreign particles.
• Wearing of the sleeve.
• Damage of the valve due to
chemical corrosion, caused
by wrong material selection
regarding media suitability.
• Check if the valve
closes completely.
• Adjustment of the
plug according to the
guideline (please refer
to pages 13 + 14).
• If the leakage cannot
be stopped the valve
has to be repaired.
External
leakage
(cover or
stem seal)
• The allowed valve operating
limits (pressure / tempera-
ture) have been exceeded.
• Wearing of the sleeve.
• Damage of the valve due to
chemical corrosion, caused
by wrong material selection
regarding media suitability.
• Cover bolting became loose
(e.g. caused by heavy vibra-
tions in the pipeline)
• Wearing resp. damage of the
cover seal.
• Adjustment of the
plug according to the
guideline (please refer
to pages 13 + 14).
• Check if the cover
bolting is fastened
properly.
• If the leakage cannot
be stopped the valve
has to be repaired.
High torque/
valve
blocks
• Possible change of the me-
dia aggregate state.
• Deposit of media on plug
resp. ball surface.
• Solid media or forgotten
installation devices in the
valve
• Remove deposits and
solid media.
Malfunction
of actuator
or acces-
sories
See corresponding
guidelines / manuals
of the manufacturer.
