OSYWT206-EN
Document is subject to change without notice.
NIPPON VALVE CONTROLS, INC.
1-21-19 Meieki minami, Nakamura-ku, Nagoya 450-0003 JAPAN
TEL: 81-52-582-6435
FAX: 81-52-582-6439
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INSTALLATION, OPERATION & MAINTENANCE INSTRUCTIONS
HANDLING & STORAGE
HANDLING
Proper care in handling the damper should be taken
to prevent damage. Do not drop or throw it.
STORAGE
Store the damper in the protected area from dust,
moisture, and direct sunlight. If possible, should be
kept in the original packaging.
CHECKING
• Check the product code before installation.
• Confirm that there is no screw loose or part
deformation.
HANDLING OF MANUAL OPERATION
• Be careful about temperature of a lever / handle part,
when using it for the fluid of the high temperature or
low.
• Avoid the operation with bare hands, and make a
protective measure.
• For manual operation, loosen the butterfly nut before
operating. After operation, tighten the butterfly nut to
secure the position.
INSTALLATION
PRECAUTIONS
Before installing, clean pipe and damper ends.
Make sure they are free of dirt, dust and etc.
PIPING FLANGES
• It has a flow direction. Install the damper accordingly.
• Gasket should be selected appropriately to suit the
fluid, pressure and temperature.
Use spring washer to prevent from decreasing surface
pressure gasket when the temperature change
happens frequently.
• Wafer type ball damper is put between two seats of
flanged-end and tightened with long bolts.
• Center the damper to the flanges accurately.
• After installation of the damper, operate the damper to
make sure the disk does not touch any part of the
piping.
• Tighten all bolts using crossover method to load the
joint evenly.
• If a plastic flange used, do not over-tighten the bolts,
as this may deform the flange and cause leakage.
ENVIRONMENT
If there is a possibility that the fluid and drive part
freeze, please take measures to prevent freezing.
POSITIONING
Should be positioned through 90° upward from
horizontal. Provide space around the product to allow
manual operation, inspection and replacement work.
INSULATION WORK
• For maintenance of gland packing, insulation should
be below the ground part.
• The upper part of the ground plate part is a heat
dissipation part, do not insulate it.
TIGHTEN THE GLAND NUTS
• Check that there is no leakage from the gland
packing.
• If it leakage, tighten gland nuts by alternately.
Do not over-tighten the gland nuts.
Recommended torques [N m]
Damper size [mm]
Torque
040 to 065
1
080 to 125
2
150 to 300
5
350 to 400
8
MAINTENANCE
Do the routine maintenance at least once in half a
year.
Inspection items
• Confirm operation of opening and closing.
• Confirm whether screws are loose or not.
• Confirm the fluid temperature or pressure.
• Confirm the leak from damper stem.
• Confirm the bolt tightening torque.
TROUBLESHOOTING
Problem
Cause
Solution
Stop in the
mid position.
There is a
foreign object
in the damper.
Remove a foreign
object.
Damper is
distorted.
Replace the damper.
Leakage
from damper
gland
Gland packing
is worn or
distorted.
Tighten the gland nut.
Replace the gland
packing.
For more information contact
NIPPON VALVE CONTROLS, INC. for consultation.
Gland nut
Gland plate
Stem
