NIBCO Technical Services • Phone: 1.888.446.4226 • Fax: 1.888.336.4226
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VI. OPERATION
Rotate the gear operator handwheel in the counter-clockwise direction to open the valve. Rotate
the handwheel in the clockwise direction to close the valve. Disc position can be determined by
looking at the pointer plate located on top of the gear operator. Note that the keys in the stem
also align with the sealing edges of the disc.
VII. REPAIR
No regular scheduled lubrication or maintenance is required except for regular exercising of the
valve. The valve needs to be fully cycled every 6 months, at a minimum, and inspected for
smooth operation and external leakage.
VIII. TROUBLESHOOTING
ISSUE POSSIBLE
REASONS
SOLUTIONS
LEAKAGE AT
VALVE SEAT
DISC IS NOT FULLY CLOSED
ADJUST GEAR OPERATOR OR
ACTUATOR CLOSE STOP - SEE
SECTION IV
CONTAMINATION ADHERED TO
SEALING SURFACES OF SEAT
CLEAN BOTH SEALING SEAT SURFACES
RUBBER SEAT HAS ERODED
CHECK MEDIA TO SEE IF COMPATIBLE
WITH RUBBER SEAT MATERIAL
EXTERNAL
LEAKAGE AT
LOWER STEM
END CAP O-RING DAMAGED
REPLACE O-RING
RETAINING COVER O-RING
DAMAGED
REPLACE O-RING
ADJUSTING SCREW O-RING
DAMAGED
REPLACE O-RING
EXTERNAL
LEAKAGE AT
UPPER STEM
STEM V-CUP PACKING WORN
EVENLY TIGHTEN PACKING GLAND
NUTS -
DO NOT OVERTIGHTEN!
STEM V-CUP PACKING
ASSEMBLY DAMAGED
REPLACE STEM V-CUP PACKING
ASSSEMBLY
LEAKAGE AT
FLANGE
CONNECTION
FLANGE BOLTS ARE NOT TIGHT
OR NOT TIGHTENED
PROPERLY
EVENLY TIGHTEN ALL FLANGE BOLTS
USING CROSS-OVER / CRISS-CROSS
PATTERN
VALVE CONNECTED TO
IMPROPER SIZE FLANGE
REVIEW FLANGE DIMENSIONS AND
COMPARE TO
TABLE 1,
INSTALL
PROPER SIZE FLANGE
SURFACES OF FLANGE ARE
CONTAMINATED
INSPECT AND CLEAN FLANGES
SURFACES OF FLANGES ARE
DAMAGED
INSPECT AND REPAIR FLANGE DAMAGE
