Removing The Valve; Packing Maintenance - Fisher A11 Instruction Manual

D Use lockout procedures to be
sure the above measures stay in effect
while you work on the equipment.
D Always wear protective gloves,
clothing and eyewear when performing
any maintenance operations to avoid
personal injury.
D The valve packing area may
contain process fluids that are
pressurized, even when the valve has
been removed from the pipeline.
Process fluids may spray out under
pressure when removing the packing
hardware or packing rings.
D Check with your process or safety
engineer for any additional measures
that must be taken to protect against
process media.
CAUTION
When using an actuator, the actuator
travel stop (or actuator, for actuators
without adjustable stops) must be
adjusted so the disc stop in the valve
does not absorb the output of the
actuator. Failure to limit the actuator
travel can result in damage to the
valve, shaft(s), or other valve
components.

Removing the Valve

For field repair, remove the valve from the pipeline.
WARNING
Using the procedures listed in the
above WARNING, loosen the flange
bolting that holds the valve. Make sure
the valve cannot slip or twist while the
bolting is being loosened and
removed.
CAUTION
Damage to the disc can occur if the
disc is not closed when the valve is
being removed from the pipeline. If
necessary, stroke the actuator to place
the disc in the closed position while
removing the valve from the pipeline.
7. Before removing the valve from the pipeline,
make sure the valve disc is closed. See figure 3.
Rotate the shaft clockwise until the disc makes
contact with the internal stop or actuator travel stop
(if still installed). The "S" stamped on the shaft
should be aligned with the "S" on the valve body.
8. After removing the valve from the pipeline, move
it to an appropriate work area. Remove the actuator
from the valve.

Packing Maintenance

The Type A11 valve is designed so the shaft packing
can be replaced without removing the valve from the
process pipeline. Refer to figure 8 for available
packing configurations and figure 9 for part key
numbers.
CAUTION
The packing flange should be
tightened only enough to prevent shaft
leakage. Excessive tightening will only
accelerate wear of the packing and
could produce higher torques on the
valve.
In most cases, packing leakage can be eliminated by
merely tightening the hex nuts located above the
packing flange while the valve is in the pipeline.
However, if leakage continues, the packing must be
replaced.
1. Before loosening any parts on the valve, be sure
the pipeline has been depressurized. Then, remove
packing nuts (key 16), lift off the packing flange
(key 12) and packing follower (key 13). The packing
(key 14) is now accessible.
2. Use a packing extractor to remove packing. Insert
the corkscrew-like end of the tool into the first piece
of packing and firmly remove. Repeat this process
until all has been removed.
CAUTION
Be careful when cleaning the packing
bore. Scratches to the valve shaft
(key 4) or inside diameter of packing
bore may cause leakage.
A11 Valve
9