Trim Removal; Ehd, Eht Valve Plug Maintenance - Fisher EHD series Instruction Manual

EH Valves NPS 8 through 14
June 2017
For spring‐loaded PTFE V‐ring packing: Tighten the packing flange nuts until the shoulder on the packing follower (key
13) contacts the bonnet (key 1).
For other kinds of packing, except ENVIRO‐SEAL and HIGH‐SEAL: Tighten the packing flange nuts to the maximum
recommended torque shown in table 5. Then, loosen the packing flange nuts and retighten them to the
recommended minimum torque in table 5.
For ENVIRO‐SEAL and HIGH‐SEAL packing: See the Fisher instruction manuals titled ENVIRO‐SEAL Packing System for
Sliding‐Stem Valves (D101642X012) or HIGH‐SEAL Live‐Loaded Packing System (D101453X012) (as appropriate) for
packing instructions.
Table 7. Seat Ring and Seat Ring Cap Screw Lubricants and Recommended Torque for Seat Ring Cap Screws
VALVE
LUBRICANT
SIZE,
NPS
8, 10
Lithium Grease
or Anti‐Seize
Lubricant
12, 14
8, 10
Dry Film
Lubricant
12, 14
16. Mount the actuator on the valve body assembly, and reconnect the actuator and valve plug stem according to the
Actuator Mounting procedure. After the control valve is returned to service, retighten the hex nuts (key 14, figure
12 or 14) to the torque recommended in table 6.

Trim Removal

WARNING
Refer to the WARNING at the beginning of the Maintenance section in this instruction manual.
For Bore seal construction, see the appropriate Bore seal sections in this instruction manual.
Key numbers referenced in this procedure are shown in figure 12 for the EHD valve and figure 14 for the EHT valve
except where indicated.
1. Remove the actuator and bonnet by following steps 1 through 9 of the Replacing Packing procedure.
2. To remove the seat ring (key 6), remove the cap screws (key 7). Install eyebolts or similar devices in the 5/8 inch
11‐UNC tapped holes (9/16 inch 12‐UNC for an NPS 8 or 10 CL1500 valve). Use the eyebolts to carefully lift the seat
ring out of the valve body. If the seat ring is to be reused, exercise care to protect the gasket surfaces on the bottom
of the seat ring.
3. Remove the spiral wound seat ring gasket or O‐ring (key 12).
4. Refer to the following appropriate valve plug maintenance procedure or to the Lapping Seats procedure.
EHD and EHT Valve Plug Maintenance
Key numbers used in this procedure are shown in figure 12 for the EHD valve and in figure 14 for the EHT valve.
12
Spiral Wound
VALVE
Gasket Construction
RATING
NSm
CL1500 61
CL2500 95
CL1500 95
CL2500 95
CL1500 47
CL2500 75
CL1500 75
CL2500 75
Instruction Manual
RECOMMENDED TORQUE
O‐Ring Construction or
Constructions for
Sour Gas Service
lbfSft NSm
45 41
70 61
70 61
70 61
35 34
55 47
55 47
55 47
D100392X012
lbfSft
30
45
45
45
25
35
35
35