RESILIENT-SEATED CARTRIDGE STYLE
FNW7XX
BUTTERFLY VALVE
INSTALLATION INSTRUCTIONS
FNW.COM
We reserve the right to modify or improve the designs or
specifications of our products at any time without notice.
14
Problem
Main Cause
Countermeasure/Remedy
The
valve
does
not work.
Faulty
operation
The disc interferes with the piping or other devices.
Insert a short pipe or spacer between the valve and flange to avoid
interference. (Section 8) 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 damaged.
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 misaligned, 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. Loose the bolts and re-tighten them by diagonal sequence.
(Refer to “Piping bolt tightening procedures”)
Increased torque due to presence of foreign
material in the piping.
Set the valve to the full-open position and flush the foreign material
out to remove it. 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 specifications.
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:
•
The rated supply pneumatic pressure and the supply amount
are secure.
•
The bypass valve is closed.
•
The operation air stop valve is open.
•
The speed controller is open properly.
•
The exhaust port plug has been removed.
For motors, check the following items:
•
The rated power voltage is supplied.
•
Voltage is applied to the motor properly.
•
The thermal protector, etc. is not activated.
•
Two or more actuators are not operated with one switch.
•
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 applied.
If a support is installed to the valve neck section or actuator, the
support may produce a force that deforms the valve.
Remove the support member and check the valve.
Abnormal interference of the disc due to damage
or deformation of the seat.
Replace the seat. 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 is applicable, the valve parts may be damaged
and replacement of the parts may be required. Please contact our
sales department.