ES Valve
Instruction Manual
December 2008
11
Table 5. Valve Stem Connection Torque and Pin Replacement
VALVE STEM CONNECTION (VSC)
BOLT TORQUE, MINIMUM TO MAXIMUM
HOLE SIZE
mm
Inches
N
S
m
Lbf
S
ft
mm
Inch
9.5
12.7
19.1
25.4
31.8
3/8
1/2
3/4
1
1-1/4
40-47
81-115
237-339
420-481
827-908
25-35
60-85
175-250
310-355
610-670
2.41 - 2.46
3.20 - 3.25
4.80 - 4.88
6.38 - 6.45
6.38 - 6.45
0.095 - 0.097
0.126 - 0.128
0.189 - 0.192
0.251 - 0.254
0.251 - 0.254
Table 6. Standard Material Designations
Standard
Designation
Common Name
or Trade Name
CoCr-A Hardfacing Alloy
R30006
S17400 SST
S31600 SST
CoCr-A
Alloy 6 Casting
17-4PH Stainless Steel
316 Stainless Steel
S41000, S41600, CA15
WCC Carbon Steel Casting
13Cr 400-Series SST
WCC
CAUTION
To avoid damaging the ENVIRO-SEAL
bellows seal bonnet assembly, do not
attempt to lap the metal seating
surfaces. The design of the assembly
prevents rotation of the stem and any
forced lapping rotation will damage
internal components of the
ENVIRO-SEAL bellows seal bonnet.
Lapping Metal Seats
A certain amount of leakage should be expected
with metal-to-metal seating in any valve body. If the
leakage becomes excessive, however, the condition
of the seating surfaces of the valve plug and seat
ring can be improved by lapping. (Deep nicks should
be machined out rather than ground out.) Use a
good quality lapping compound of a mixture of 280
to 600-grit. Apply the compound to the bottom of the
valve plug.
Assemble the valve to the extent that the cage and
the cage retainer and bonnet spacer (if used) are in
place and the bonnet is bolted to the valve body. A
simple handle can be made from a piece of strap
iron locked to the valve plug stem with nuts. Rotate
the handle alternately in each direction to lap the
seats. After lapping, remove the bonnet and clean
the seat surfaces. Completely assemble as
described in the assembly portion of the trim
maintenance procedure and test the valve for
shutoff. Repeat the lapping procedure if leakage is
still excessive.
CAUTION
To avoid weakening the stem or
adaptor that may cause failure in
service, never reuse an old stem or
adaptor with a new valve plug. Using
an old stem or adaptor with a new plug
requires drilling a new pin hole in the
stem (or adaptor in case an
ENVIRO-SEAL bellows seal bonnet is
being used), which will weaken the
stem. However, a used valve plug may
be reused with a new stem or adaptor.
Valve Plug Maintenance
Except where indicated, key numbers are referenced
in figure 13 for NPS 1/2 through 6 constructions,
figure 14 for NPS 8 ES valves, figure 15 for Whisper
Trim III cage detail, and figure 16 for WhisperFlo
trim.
1. Remove the valve plug (key 2) according to the
disassembly portion of the trim maintenance
procedure.
2. To replace the valve stem (key 7), drive out the
pin (key 8). Unscrew the valve plug from the stem or
adaptor.
3. To replace the adaptor (key 24, figure 8) on
ENVIRO-SEAL bellows seal bonnets, place the plug
stem assembly and valve plug in a soft-jaw chuck or
other type of vise so that the jaws grip a portion of
the valve plug that is not a seating surface. Drive out
or drill out the pin (key 36, figure 8). Reverse the
plug stem assembly in the soft-jaw chuck or vise.
Grip the flat areas on the valve stem just below the
threads for the actuator/stem connection. Unscrew
the valve plug/adaptor assembly (key 24, figure 8)
from the valve stem assembly (key 20, figure 8).
4. Screw the stem or adaptor into the valve plug.
Tighten to the torque value given in table 5. Refer to
table 5 to select the proper hole size. Drill through
the stem or adaptor, using the hole in the valve plug
as a guide. Remove any chips or burrs and drive in a
new pin to lock the assembly.
5. For ENVIRO-SEAL bellows seal bonnets, grip the
flats of the stem extending out of the top of the
