6
RESILIENT SEAT REPLACEMENT INSTRUCTIONS
CAUTION
Follow required safety procedure and policies.
Assure line is not pressurized before loosening
packing and removing valve. Use proper lifting
and support techniques when moving valve and
or valve subassemblies.
Tools and materials required:
1. Open end wrenches or sockets to fit
packing gland and four-post yoke hex nuts.
2. Flat head screwdriver.
KEYSTONE
FIGURE PCS17 KNIFE GATE VALVES
INSTRUCTION, OPERATION AND MAINTENANCE MANUAL
DISASSEMBLY
1. Flush line to remove solids and
contaminants from chest and seat channel
area, drain when flushing is complete.
2. Relieve pressure on valve/pipeline.
3. Remove packing gland hex nuts and loosen
packing gland. (Figure 9)
4. Fully open the valve.
5. Detach gate from valve lifter by removing
gate bolts.
6. Remove top plate hex nuts and washers
from four-post yoke.
7. Pull entire actuator assembly up and away
from valve, set aside.
8. Pull gate from valve body (examine gate for
flatness and damage, replace if necessary).
9. Thoroughly remove old packing.
10. Remove seat.
Note:
to remove seat, it will be necessary
to slip a pry tool through the gate slot in the
packing support bar and pry up and out of the
valve body. Seat will most likely be damaged
beyond use when pulled from body.
Do not pull seat from body unless
replacement is planned for. A special tool is
available for this purpose, refer to Figure 10.
See chart for part number and description.
11. Closely examine packing box, valve chest
and seat channel. Remove any remaining
solids from seat channel.
Seat shown out of valve for clarity
Top plate hex nuts
(located on top of
yoke posts)
Gate bolts
Packing gland
Packing gland
hex nuts
FIGURE 9
FIGURE 10
