28
EB 2183 EN
Decommissioning and removal
Table 5:
Troubleshooting
Malfunction
Possible reasons
Recommended action
The temperature adjusted at the
control thermostat reaches the
adjusted temperature limit.
Control thermostat defective
Î
Replace the control thermostat.
Temperature exceeds the adjusted
limit.
Foreign particles blocking the valve
plug
Î
Remove foreign particles.
Î
Replace damaged parts.
Valve trim is worn out.
Î
Replace damaged parts.
Increased flow through closed valve
(seat leakage).
Foreign particles blocking the valve
plug
Î
Remove foreign particles.
Î
Replace damaged parts.
Valve trim, particularly with soft seat,
is worn.
Î
Replace damaged parts.
Heat supply has been interrupted.
STM is defective and has moved to
the fail-safe position.
Î
Replace the STM.
Temperature sensor not correctly
installed.
Î
Check installation. Observe notes
on installation (see section 5.4).
Strainer blocked
Î
Clean the strainer.
9 Decommissioning and
removal
Risk of bursting in pressure equipment.
Valves and pipelines are pressure equip-
ment. Improper opening can lead to valve
components bursting.
− Before starting any work on the valve, de
-
pressurize all plant sections affected as
well as the valve.
−
Drain the process medium from all the
plant sections affected as well as the valve.
−
Wear personal protective equipment.
DANGER
!
Risk of personal injury due to residual pro-
cess medium in the valve.
While working on the valve, residual me-
dium can flow out of the valve and, depend
-
ing on its properties, cause personal injury,
e.g. (chemical) burns.
−
If possible, drain the process medium from
all the plant sections affected and the
valve.
−
Wear protective clothing, safety gloves and
eye protection.
WARNING
!