UNIWORLD Series
M/UNIWORLD-M/E ed. 01 2020
3.12.5
– ACTUATOR MAINTENANCE
The PSL-AMS or PSL actuators are maintenance-free, all the gears are lubricated for life and therefore do not require periodic
lubrication.
During any cleaning, use a dry cloth (not rough and non-abrasive) and do not use detergent
4
OPERATING ANOMALIES
4.1
– VALVE OPERATING ANOMALIES IN GENERAL
Some problems are outlined below which can occur during operation of the valves and the measures to implement.
PROBLEMS FOUND
CAUSE
MEASURE
The stem does not run the entire stroke
and/or stroke incomplete
1.
The actuator is not calibrated
1.
See page no. ?
2.
Waste
deposits
between
compartment and plug
2.
If seizure not generated, remove
deposits
3.
Indicator label movement compared
to index
3.
Reposition the stroke reference
based on index
4.
The instrumentation does not supply
the correct signal and is necessary to
execute stroke
4.
Search
the
causes
on
the
instrumentation
The stem moves in jolts
1.
Stem seized and/or damaged
1.
If possible, polish the stem,
otherwise replace the “trim”
2.
Sediment in packing chamber
2.
Replace the bonnet with packing
Heavy seal
compartment/plug leak
1.
Soft seal class VI damaged
1.
Replace the soft seal class VI
2.
Metal seal class IV or V damaged
2.
If possible, grind the cone of the plug
with the edge of the compartment with
“grinding paste”
Otherwise, replace the trim
3.
Differential
pressure
between
upstream and downstream of the
valve too high
3.
Contact our Servicing to ask for a
quote for replacement, if possible, of
the actuator
Packing leak
1.
Worn rings or seals
1.
Replace the bonnet with packing
2.
Soft seal broken
2.
Given the complexity of the operation,
contact our Servicing
