Replacement Of An Installed Enviro-Seal; Bellows Seal Bonnet - Fisher EWS Series Instruction Manual

EW Valve
the valve stem must not be rotated.
Damage to the bellows may result.
Do not grip the bellows shroud or
other parts of the stem/bellows
assembly. Grip only the flat areas on
the stem where it extends out of the
top of the bellows shroud.
The ENVIRO-SEAL stem/bellows
assembly has a one-piece stem.
6. To attach the valve plug to the stem of the new
ENVIRO-SEAL stem/bellows assembly, it is
necessary to first attach the plug to the adaptor
(key 24, figure 21). Locate the adaptor. Notice that a
hole has not been drilled in the threads where the
plug screws onto the adaptor. Secure the valve plug
in a soft-jaw chuck or other type of vise. Do not grip
the plug on any seating surface. Position the plug in
the chuck or vise for easy threading of the adaptor.
Thread the adaptor into the valve plug and tighten to
the appropriate torque value.
7. Select the proper size of drill bit and drill through
the adaptor using the hole in the valve plug as a
guide. Remove any metal chips or burrs and drive in
a new pin (key 8) to lock the plug/adaptor assembly
together.
8. Attach the plug/adaptor assembly to the
ENVIRO-SEAL stem/bellows assembly by first
securing the stem/bellows assembly in a soft-jaw
chuck or other type of vise so that the jaws of the
chuck or vise grip the flats of the stem extending out
of the top of the bellows shroud. Screw the valve
plug/adaptor assembly onto the valve stem. Tighten
the plug/adaptor assembly until it is snug. Then turn
the plug/adaptor assembly to the next pin hole in the
valve stem. Drive in new pin (key 36, figure 21) to
lock the assembly.
9. Inspect the seat ring (key 9). Replace, if
necessary.
10. Place a new gasket (key 10) into the valve body
in place of the bonnet gasket. Install the new
stem/bellows assembly with valve plug/adaptor by
placing it into the valve body on top of the new
bellows gasket.
11. Place a new gasket (key 22, figure 21) over the
stem/bellows assembly. Place the new
ENVIRO-SEAL bonnet over the stem/bellows
assembly.
12. Properly lubricate the bonnet stud bolts. Install
and tighten the bonnet hex nuts to the proper torque.
22
Note
Table 8. Recommended Torque for ENVIRO-SEALr
Bellows Seal Bonnet Packing Flange Nuts
VALVE
MINIMUM TORQUE
VALVE
STEM
SIZE, SIZE,
DIAMETER DIAMETER
NPS
THROUGH
NSm
PACKING
4x2 1/2
6x4 to
1
12x8
13. Install the new packing and the metal packing
box parts according to the appropriate arrangement
in figure 15 or 16.
14. Install the packing flange. Properly lubricate the
packing flange stud bolts and the faces of the
packing flange nuts.
For graphite packing, tighten the packing flange
nuts to the maximum recommended torque shown in
table 8. Then, loosen the packing flange nuts, and
retighten them to the recommended minimum torque
shown in table 8.
For other packing types, tighten the packing flange
nuts alternately in small equal increments until one
of the nuts reaches the minimum recommended
torque shown in table 8. Then, tighten the remaining
flange nut until the packing flange is level and at
a 90-degree angle to the valve stem.
15. Install the travel indicator parts and stem
locknuts; mount the actuator on the valve body
according to the procedure in the appropriate
actuator instruction manual.
Replacement of an Installed
ENVIRO-SEAL Bellows Seal Bonnet
(Stem/Bellows Assembly)
1. Remove the actuator and bonnet according to
steps 1 through 6 of the Replacing Packing
procedure of the Maintenance section.
2. Lift out the cage. Remove and discard the
existing bonnet gasket and bellows gasket. Cover
the valve body opening to protect sealing surfaces
and to prevent foreign material from entering the
valve body cavity.
CAUTION
The ENVIRO-SEAL stem/bellows
assembly for Design E valves is
available only with a threaded and
pinned plug/adaptor/stem connection.
The existing valve plug can be reused
with the new stem/bellows assembly
Instruction Manual
Form 2376
March 2007
MAXIMUM
TORQUE
LbfSin NSm LbfSin
2 22 4
5 44 8
33
67