Val-Matic Rubber-Seated Ball 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 seat 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. 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 with liquid gasket material
such as Permatex Ultra-Blue RTV..
 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. Lay the longer half of the body on the floor or saw
horses. Remove the body bolts (19) and lift the
short body half (1B) from the valve.
3. 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 (24). Access to the traveling nut actuator
will be under the actuator cover.
4. Remove cap (20) and thrust bearing (18), and
thrust bearing shims (17). Remove the seat bolts
(8) and seat retaining ring (7).
5. Remove the taper pin bolts (11) and taper pins (9).
Pull out the shaft (4). The bearings (5) should not
be removed unless the teflon liner is severely
worn. To remove bearings, grind a slot along its
length and hammer out with a sharp chisel.
6. Remove grit seats (10) if damaged or worn.
7. 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.