Val-Matic 3-24 Butterfly Valve - Manual (Page 10)

10
TROUBLESHOOTING
Several problems and solutions are presented below
to assist you in troubleshooting the valve assembly
in an efficient manner.
Leakage at Valve Shaft: Replace packing.
Leakage at Flanges: Tighten flange bolts, replace
gasket.
Valve Leaks when Closed: Flush debris from seat by
cycling valve. Adjust actuator closed stop. Inspect
seat for damage and adjust seat bolts 1/4 turn at a
time.
If the valve continues to leak after adjustment, check
for the following items and make the corrections.
1. Verify that there is no damage to the rubber
seat. Replace if torn or damaged.
2. Check that the metal set in the body is clean
and free of scale and scratches.
3. Check that the actuator is fully closed and the
seal is centered in the body seat. Adjustment
to the actuator stop nuts or bolts may be
necessary.
4. Check the roundness of the adjoining pipe and
pipe flange. Pipe loads may cause distortion to
the adjoining pipe and valve.
5. Verify that the test pressure is less than the
cold working pressure (CWP) shown on the
valve nameplate.
 Hard to Open: Flush line of debris. Check
grease in actuator. Check interior of valve for
deposits or debris. On buried valves, check
alignment of operating stem and nut.
 Leaking Oil: Tighten actuator cover bolts. If leak
persists, remove actuator cover, inspect grease,
and replace actuator gasket.
 Noisy Operation: Flow noise is normal. Loud
flow noise similar to hammering may be cavitation
from dropping high pressures across valve; review
application of valve. For gear actuator noise,
inspect grease; add new grease if there are
uncoated moving parts or grease has broken
down into oil.
DISASSEMBLY
Disassembly may be required to repair the valve.
Work on the valve should be performed by a skilled
mechanic with proper tools and a power hoist for
large valves. The valve must be removed from the
pipeline for disassembly. The actuator can be
removed with the valve in the line (the line must be
drained) or after the valve is removed from the line.
Refer to Figure 2 for valve construction and parts.
1. Open valve slightly and drain the pipeline.
Close valve until disc edge just touches the
seat. Valve and actuator can be removed as a
unit from the pipeline.
2. Remove the small cover on the actuator to
expose the shaft key. Remove the actuator
mounting bolts and lift actuator from valve
taking care not to lose key (14). Access to the
traveling nut actuator will be under the actuator
cover.
3. Remove bottom cap screws (16) and thrust
bearing cap (15). Remove the seat bolts (8)
and seat retaining ring (7).
4. Matchmark the taper pins with the disc holes.
Remove the taper pin nuts (11) and taper pins
(9). Press or hammer out the shaft (4) with a
dead blow hammer. The bearings (5) will likely
be pushed out with the shaft.
5. Clean and inspect parts. Replace worn parts
as necessary and lubricate parts with FDA
grease.
WARNING: Open valve and drain line before
removing actuator or the valve
may suddenly open causing
injury or fluid loss. Place valve in
closed or slightly open position
to remove from the line or
damage to the disc edge may
occur.