Replacement Of Installed Bore Seal Trim; Trim Removal (Bore Seal Constructions) - Emerson Fisher EU Instruction Manual

EU and EW Series Valves
July 2017
CAUTION
Do not remove the existing valve stem from the valve plug unless you are planning to replace the valve stem.
Never reuse an old valve stem with a new plug or reinstall a valve stem after it has been removed. Replacing a valve stem
requires drilling a new pin hole in the stem. This drilling weakens the stem and may cause failure in service. However, a
used valve plug may be reused with a new valve stem.
11. Remove the existing valve stem and plug, cage, and seat ring from the valve body following the appropriate
instructions in the Trim Removal section of this manual.
12. Replace all gaskets according to appropriate instructions in the Trim Replacement section of this manual.
13. Install the new seat ring, cage, valve plug/retainer assembly, and stem into the valve body and completely
reassemble the valve package following the appropriate instructions in the Trim Replacement section of this
manual.
CAUTION
To avoid excessive leakage and seat erosion, the valve plug must be initially seated with sufficient force to overcome the
resistance of the Bore Seal and contact the seat ring. You can correctly seat the valve plug by using the same force
calculated for full load when sizing your actuator. With no pressure drop across the valve, this force will adequately drive
the valve plug to the seat ring, thus giving the Bore Seal a predetermined permanent set.
With full actuator force applied and the valve plug fully seated, align the actuator travel indicator scale with the lower end
of valve travel. Refer to the appropriate actuator instruction manual for information on this procedure.

Replacement of Installed Bore Seal Trim

Trim Removal (Bore Seal Constructions)

1. Remove the valve actuator and bonnet following the appropriate instructions in the Replacing Packing section of
this manual.
CAUTION
To avoid leakage when the valve is returned to service, use appropriate methods and materials to protect all sealing
surfaces of the trim parts during maintenance.
Use caution when removing piston ring(s) and the Bore Seal to avoid scratching any sealing surface.
CAUTION
Do not remove the valve stem from the plug/retainer assembly unless you are planning to replace the valve stem.
Never reuse an old valve stem with a new plug or reinstall a valve stem after it has been removed. Replacing a valve stem
requires drilling a new pin hole in the stem. This drilling weakens the stem and may cause failure in service. However, a
used valve plug may be reused with a new valve stem.
2. Remove the plug/retainer assembly (with Bore Seal), cage, and seat ring from the valve body following the
appropriate instructions in the Trim Removal section of this manual.
3. Locate the staked thread on top of the valve plug (figure 10). The staked thread secures the retainer. Use a drill with
a 1/8 inch bit to drill out the staked area of the thread. Drill approximately 1/8 inch into the metal to remove the
staking.
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Instruction Manual
D102010X012