Fisher HPA Instruction Manual page 25

Instruction Manual
D101634X012
3. Place the C‐seal plug seal over the top of the valve plug and press the C‐seal plug seal onto the plug using the C‐seal
installation tool. Carefully press the C‐seal plug seal onto the plug until the installation tool contacts the horizontal
reference surface of the valve plug (figure 13).
4. Apply a suitable high‐temperature lubricant to the threads on the plug. Then, place the C‐seal retainer onto the
plug and tighten the retainer using an appropriate tool such as a strap wrench.
5. Using an appropriate tool such as a center punch, stake the threads on top of the plug in one place (figure 14) to
secure the C‐seal retainer.
6. Install the new plug/retainer assembly with C‐seal plug seal on the new stem following the appropriate instructions
in the Trim Replacement section in this manual.
7. Install piston rings by following instructions in the Trim Replacement section in this manual.
8. Remove the existing valve actuator and bonnet following the appropriate instructions in the Replacing Packing
section in this manual.
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.
9. Remove the existing valve stem and plug, cage, and seat ring from the valve body following the appropriate
instructions in the Trim Removal section in this manual.
10. Replace all gaskets according to appropriate instructions in the Trim Replacement section in this manual.
11. 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 in this
manual.
Figure 13. Installing the C‐seal Plug Seal Using the Installation Tool
INSTALLATION
TOOL
C‐SEAL
METAL
PLUG
SEAL
A6778
FLOW DOWN
NOTE: PRESS THE INSTALLATION TOOL OVER THE VALVE PLUG UNTIL THE TOOL CONTACTS THE HORIZONTAL REFERENCE SURFACE OF THE VALVE PLUG.
VALVE
PLUG
HORIZONTAL
REFERENCE
SURFACE
HP and HPA Valves
July 2017
25