Series 91000
••• Self-Operating Regulators
Operation, Installation & Maintenance Manual
Page 9
STEM SEAL PACKING
The regulator uses Teflon “V” ring packing sets with stainless steel male and female adapters used as end rings,
with a stainless steel compression spring. This spring loading of the packing maintains proper compression of
the rings and also compensates for wear that occurs at the seals. No adjustment is need and the packing nut
should always be threaded all the way onto the bonnet, but only finger tight. Replacement packing sets are
available from the factory.
REPLACING Valve Stem Packing
1.
Remove the valve assembly from the actuator. See section on “Removing Valve Body Assembly”.
Do not grip or scratch the polished stem surface. This polish is part of the sealing system.
2.
With the valve fully closed, measure and record the location of the two stem locknuts relative to their
distance from the face of the bonnet. This dimension will be required for reassembly.
3.
Loosen and remove both stem locknuts.
4.
Remove the packing nut from the valve bonnet.
5.
Remove all old packing, adapters and spring from the valve bonnet. One technique is to admit a small
amount of pressure into the valve body until the packing is forced out of the stuffing box. Shield the bonnet
as some spray may occur as the packing emerges.
DO NOT SCRATCH THE BORE OF THE STUFFING BOX WITH SHARP TOOLS.
6.
Clean all surfaces of the stuffing box and stem. Remove all accumulations of mineral deposits or other
debris before re-building. A .4375 diameter reamer is ideal to remove deposits from the bonnet, if the
bonnet is removed from the body. A .45 diameter brass brush is often also very effective. Do not use
abrasives on the valve stem nor in the stuffing box since scratches will cause leakage. The valve stem
originally was polished to a 12 micro-inch finish and this polish should be preserved. If the stem is
corroded, worn or marred it must be replaced. See section on “Reversing Valve Action”.
7.
Blow all debris from the stuffing box and the replacement packing before re-building.
PACKING MUST BE CLEAN & FREE OF FOREIGN MATERIAL.
8.
Install new packing as follows:
A) – Spring
B) – Male adapter with flat side in first against spring.
C) – V rings with lips in first. (3 pieces)
“V” rings must be carefully installed over the stem threads and into
the stuffing box bore to avoid snagging of the lips on threads of
bore entrance since the clean edge on these lips is imperative for
proper sealing.
D) – Female adapter with cavity in against “V” rings and flat side out.
E) – Packing nut.
9.
Tighten packing nut all the way down onto the bonnet to push all rings down into the stuffing box and to
obtain proper spring load on the assembled rings.
TIGHTEN FINGER TIGHT ONLY.
10.
Replace the stem locknuts and re-position and lock in place as previously measured in step 2. If this
dimension is not available, see section on “Replacing Valve Body Assembly” and use the dimension as
described in the table there
11.
Re-assemble Valve Body to Actuator as shown in section titled “Replacing Valve Body Assembly”.
E
D
B
A
C
