172-65097M-05 (CV10 Control Valve) 7 Oct 2021
22
Troubleshooting
When disassembling or removing the product, wait until the internal
pressure equals atmospheric pressure and the surface of the product
has cooled to room temperature. Disassembling or removing the
product when it is hot or under pressure may lead to discharge of fluids,
causing burns, other injuries or damage.
CAUTION
Be sure to use only the recommended components when repairing the
product, and NEVER attempt to modify the product in any way. Failure to
observe these precautions may result in damage to the product or burns
or other injury due to malfunction or the discharge of fluids.
CAUTION
If the product fails to operate properly, use the following table to locate the cause and
remedy.
Problem
Cause
Diagnosis/Inspection
Remedy
Valve leakage
The supply air pressure
to the positioner is too
high
Check the supply air
pressure to the positioner
(confirm product
specifications)
Reset the positioner
’s
supply air pressure;
adjust the positioner
’s
zero point
The positioner
’s zero
point is off
Check the pressure on
the positioner
’s pressure
gauge when the input
signal is at zero
If the pressure on the
pressure gauge attached
to the positioner is raised,
adjust the
positioner’s
zero point
The inlet pressure for the
control valve is too high
Check the inlet pressure
for the control valve
Reduce the inlet pressure
(Cv value and spring
range must be changed)
The valve and valve seat
are off-center
Move the valve stem up
and down and check to
see if it catches
Reassemble the bonnet
section correctly
The valve and valve seat
are worn
Check the valve and
valve seat
Replace with a new valve
and valve seat (use valve
and valve seat of a
different material than the
ones being replaced)
Control valve
opening does not
move beyond a
certain point
The bellowphragm in the
actuator is broken
Check to see if air is
leaking from the exhaust
tap or bellowphragm area
Replace with a new
bellowphragm (check to
make sure that the
ambient temperature is
not too high)
Internal parts of the
positioner are broken (the
diaphragm is cracked,
etc.)
Check to see if any
abnormal noise is coming
from the positioner
Replace with a new
positioner
(check to see if the valve
opening (travel) is
changing frequently, and
the ambient temperature
is too high)
Supply air pressure to the
positioner is insufficient
Check the supply air
pressure for the
positioner (refer to the
product specifications)
Adjust the supply air
pressure for the
positioner (refer to the
product specifications)
Controller set incorrectly Check to see if an input
signal of 4-20 mA is
coming from the controller
Verify the controller
setting and correct if
necessary
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