2021/12
5.Operating Problems: Causes and Solutions
11
5.
Operating Problems: Causes and
Solutions
PROBLEM
CAUSE/EFFECT
SOLUTION
AIR LEAKING
THROUGH LEAK
DETECTOR
The O-ring on the shaft is worn or damaged.
•
Replace the O-ring.
AIR LEAKING
THROUGH EXIT
The O-ring of the piston is worn or damaged.
•
Plastic actuator: replace the O-ring
•
St.Steel actuator: replace the
actuator
FLUID LEAKING
THROUGH LEAK
DETECTOR
Diaphragm is damaged
•
Replace diaphragm
EXTERNAL FLUID
LEAK (BETWEEN
ACTUATOR AND
BODY)
Diaphragm not properly attached
Screws between body and actuator are loose
Diaphragm is damaged
•
Disassemble the valve and attach
correctly.
•
Tighten the screws
•
Replace diaphragm
INTERNAL FLUID
LEAK
(VALVE CLOSED)
Normal wear of the diaphragm.
•
Replace the diaphragm.
Manual valve with closed improperly adjusted
•
Check according to chapter 7.2
Premature
wearing of
the
diaphragms
Diaphragm worn or affected by the fluid.
Excessive pressure in the line.
Working temperature too high
Loss of watertightness (vibration).
Tight too much the valve with the manual
handle.
•
Replace the diaphragm with
another of different material and
more appropriate to the fluid.
•
Tighten any loose components.
•
Clean frequently.
•
In NO and A/A actuators, reduce
air pressure.
•
Turn the handle only for closing
the valve.
Overpressure
•
Increase the compressed air
pressure.
•
Replace the actuator with a dual-
effect one.
VALVE DOES NOT
OPEN/CLOSE
Diaphragm deformed.
Diaphragm not properly attached.
Close manual valve improperly adjusted
Actuator bush in poor condition and/or jammed (dirtiness)
Excessive pressure on plug
•
Replace the diaphragm with
another of different quality, if
prematurely deteriorated.
•
Attach diaphragm correctly.
•
Check according to chapter 7.2
•
Replace bush (clean)/ replace
actuator
•
Reduce pipework pressure.
SURGE
The valve closes too fast.
•
Adjust the closing speed of the
actuator (with a flow regulator).
