REVERSING THE VALVE ACTION
(continued)
Series 91000
••• Self-Operating Regulators
Operation, Installation & Maintenance Manual
Page 15
Procedure
1.
Remove the valve body from the actuator as instructed in “Removing Valve Body Assembly”.
2.
Unlock and remove the two stem locknuts.
3.
Carefully remove the stem packing. See “Replacing Valve Stem Packing”. Place packing in a safe
CLEAN
area.
4.
Using lengths of pipe in the union ends to hold the valve body, remove both the bonnet and the bottom plug from
the valve body. See Figure 7. (Never use a wrench or vise on the bronze body.)
5.
Look into the valve body on the side the valve plug was removed from. Make a note as to the appearance of the
valve seats. The stainless steel valve seats are single sided. During reassembly the valve plug must be reinstalled
through this side of the valve body.
6.
Remove valve plug from bonnet as shown in Figure 7.
7.
A cross pin secures the stem from rotating in the valve plug. Remove this pin carefully with a drift
without marring the components. See Figure 8.
8.
Unthread the stem from the valve plug. See Figure 9.
9.
Thread the stem into the opposite end of the valve plug as shown in Figure 10.
A) Thread the stem in until the cross pin holes in the stem and the valve plug are centered upon each other.
B) Check the centering by making an extra 1/2 turn to see if this improves the centering. If not then 1/2 turn back.
10.
Replace the cross pin.
A) If the holes are aligned correctly, when holding the valve plug by the valve stem and shaking it like a rattle,
an audible rattle will be both felt and heard.
B) The cross pin must not protrude from either side of the valve plug.
11.
The valve may now be assembled with the valve plug entering the valve body from the side presenting the stainless
steel seat faces. See Figures 11 & 12. Note that the arrow cast on the side of the body appears to have been
reversed, and (not shown in the picture) the lettering on the other side is now upside down relative to when you started.
12.
Carefully slide the bonnet over the valve stem and attach to valve body using a suitable thread compound.
13.
Reinstall the packing set. See “Replacing Valve Stem Packing”.
14.
Install the bottom plug using a suitable thread compound.
15.
Replace the locknuts and reassemble the valve to the actuator per the instructions in the section
“Replacing the Valve Body Assembly”.
NOTE: The arrow
cast on the valve
body always
points in the
correct direction
of flow for both
assemblies.
Figure 10
Figure 11
Figure 12
Stem moves out of body to
close assembly.
