Badger Meter Research Control Valve - Manual (Page 7)

Packing, Chevron Ring
1. Proceed with disassembly of body-bonnet assem-
bly as in changing trims.
2. Remove the packing gland and all components from
within the cavity. If the Teflon packing follower has been
damaged due to over tightening and extruded into the
threads of the packing cavity, a standard screwdriver
can be driven into the teflon to unscrew the follower. ln
this case, the packing follower needs to be replaced.
3. Clean and inspect cavity and parts for damage.
4. Place packing adaptor in the cavity making sure the
flat side is down and in place.
5. Place the first ring into the cavity at a 90 degree
angle to its seated position. When the ring is at the
bottom of the cavity, tip it over with the cup side down
using a small plastic or wooden probe. Continue this
procedure with the two additional rings. This method
prevents the threads of the cavity from damaging the
lips of the rings.
6. Place the packing follower on top of the rings, making
sure the inverted “V” is down. (The arrangement for
reversed Cv ring vacuum packing requires special parts.)
7. Replace the packing gland. Tighten until contact is
made with the packing follower.
8. If the plug portion of the trim is machined integral on
the stem, the stem connector should be tightened onto
the stem before insertion into the bonnet and may be
inserted through the packing from the top of the bonnet.
If the plug portion of the trim is screwed onto the stem,
the stem should be placed through the packing from
the bottom of the bonnet by gently screwing the stem
threads through the packing. The stem connector can
then be tightened onto the stem.
9. Retract the stem sufficiently to keep the trim from
seating and screw the bonnet into the body. Be sure to
install gasket.
10. Apply the proper torque to bonnet/body joint as listed
on the back side of individual technical briefs under
pressure/temperature ratings.
11. Proceed with assembly and adjustments per Page
3.
12. Test packing by tightening gland 1/4 turn past
fingertight. Do initial test with low pressure (80 to 100
psi). If packing leaks, tighten gland just until leak stops.
Excess torque can damage Teflon components. Once
this procedure is complete, the valve can be tested at
higher pressures.
CAUTION: Do not tighten gland more than is necessary
to stop leaks.
NOTE: On valves supplied prior to October 1993, the
packing follower on all valves was virgin Teflon and
packing adaptor was the same metal material as valve.
To improve on the total packing function in regard to
sealing and replacement, both the follower and adaptor
materials have been changed to now available, Teflon
PFA. This denser Teflon material allows the guide
diameter to be closer for better alignment and solves
the cold flow problem of the original virgin Teflon follower.
Braided Teflon and Graphoil
The original packing for Research Control Valves was
braided Teflon which used a smaller gland nut. After
molded chevron rings became available and for a period
of time, there was a difference between the bonnet
packing cavity, depending on type of packing used. The
components parts were not interchangeable until the
current design was introduced in 1972, standard 1981,
using a common cavity for all types packing.
1. Braided Teflon is available and used in current packing
cavity by putting in a dummy stem to fit the packing
over as shown in Figure 11. Fill the cavity
with sock or rope type packing, tamping into the cavity
with a packing tool or piece of appropriate size copper
tubing as shown in Figure 12, until cavity is full with a
couple threads showing. Screw gland in and tighten to
compress packing.
FIG. 11
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