26
7. 1 Troubleshooting
(Continued)
Problem
Main Cause
Countermeasure
4. The valve does not
work.
Faulty operation
[Fig.-43]
The disc interferes with the pip-
ing or other devices.
Insert a short pipe or spacer between the valve and flange to
avoid interference. (section
6. 1) In this case, remove and check
the disc sealing part because there is a high possibility that it is
damaged.
The valve is deformed or dam-
aged.
Check the appearance of the body, disc and shaft to ensure that
there is no deformation, dent, damage, corrosion, etc. If any of
these are observed, replace the valve.
Actuator parts are damaged.
For details, refer to the instruction manual of the actuator.
The piping bolts are loose or
tightened unevenly.
The valve is misaligned.
The pipe flanges are mis-
aligned, are not parallel, or
distorted.
If tightening force of the bolts is uneven or the contact areas are
not equal, the valve seat compression is uneven and the torque
may increase. Loosen the bolts and retighten them by diagonal
sequence. (section
3. 4. 2-6),10), section 4. 1. 1-10) “Piping bolt
tightening procedures”)
Increased torque due to pres-
ence of foreign material in the
piping.
Set the valve to the full-open position and flush the foreign material
out to remove it.
(section
3.6.6-4)) In this case, remove and check the disc sealing
part because there is a high possibility that it is damaged.
Powdered foreign material
inside the piping enters the
bearings.
If rust powder or powdered foreign material is inside the piping, any
foreign material which entered the bearings may interfere with the shaft
rotation.
If there is a possibility of this remove the valve and clean it.
The product specifications do
not conform to the fluid specifi-
cations.
For automatic valves, the actuator size is selected in accordance
with the working conditions (temperature, pressure, flow rate,
fluid type). If the working conditions are changed, the valve may
not work due to insufficient actuator torque.
Please contact our sales department.
The actuator rated output is not
available.
(For automatic valves)
For cylinders, check the following items.
1) The rated supply pneumatic pressure and the supply amount
are secure.
2) The bypass valve is closed.
3) The operation air stop valve is open.
4) The speed controller is open properly.
5) The exhaust port plug has been removed.
For motors, check the following items.
1) The rated power voltage is supplied.
2) Voltage is applied to the motor properly.
3) The thermal protector, etc. is not activated.
4) Two or more actuators are not operated with one switch.
5) No water is inside the motor.
For details, refer to the instruction manual of each actuator.
The valve body is deformed
because abnormal force is ap-
plied.
If a support is installed to the valve neck section or actuator, the sup-
port may produce a force that deforms the valve.
Remove the support member and check the valve.
If this product interferes with other devices or buildings, the force is
produced too. Avoid the interference of the product.
Abnormal interference of the
disc due to damage or deforma-
tion of the Seatring.
Replace the Seatring.
If any abnormality is observed on the disc edge, replace the
valve.
Parts, such as the disc, shaft,
body and joint, are damaged.
If none of the above are applicable, the valve parts may be dam-
aged, and replacement of the parts may be required. Please
contact our sales department.
Summary of Contents for 304YA
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