Badger Meter Research Control Valve - Manual (Page 5)

4. Torque seat firmly into body with the short T- handle
assembly. Check seat to body seal, by making body a
bubble chamber, using a pointed plastic plug in seat to
seal as shown in Figure 5 with downstream port plugged
and 50 psi air pressure upstream, check for leak. If
leak exists, re-torque seat and recheck until bubble-
tight seal is accomplished. On smaller letter or “P” series
trim sets, over-torquing seat in the body can reduce the
orifice size to where interference between innervalve
and seat can cause a premature mechanical failure
(galling) when stroking valve.
FIG. 5
5. With body in vise, again clamping across ends of
body not sides of body, place body bonnet gasket in
place. (Process permitting, coat each side of gasket
with lubricant such as Dow Corning or Dupont Krytox
valve seal.) With the stem section of the trim set
installed in the bonnet, coat the bonnet threads (body
end) with lubricant.
6. Screw bonnet into body and tighten with open-end or
crescent wrench. Apply the proper torque to bonnet/
body joint as listed on the back side of individual
technical briefs.
7. Stroke innervalve manually to check for misalign-
ment. Should misalignment exist, check straightness
of innervalve or packing. (See Packing Installation.)
NOTE: All replacement trim sets have been prelapped
at the factory. When installed per instructions, trims
should leak no more than 1/10 of one percent of
maximum flow for the given size, (ANSI Class III). If
necessary, with care, bubble-tight shutoff can normally
be achieved by lapping in seating surfaces with the
innervalve set installed in the body bonnet assembly
using lapping compound (white aluminum oxide 38-1000
grit) with the packing removed, using the packing glands
as the upper guide (brass lap bushing available at
factory). See Figure 6. Lapping should be done with a
clockwise, counterclockwise motion between the thumb
and forefinger, lifting the innervalve off seat and
repositioning periodically to achieve a uniform lap ring.
After each lapping operation, remove bonnet from body
and clean innervalve and seat from body. Clean seat by
submerging body in solvent and swabbing orifice with
wetted pipe cleaner and blow dry with air. After cleaning,
reassemble and check leak rate as shown in Figure 7.
Caution should be taken to not overlap.
Lapping Sequence
Lap for about 30 seconds, clean and check leak rate;
repeat sequence until desired shutoff is achieved. If
after lapping three or four times leak still exists, check
the seating surfaces of both innervalve and seat for
excess nicks, scratches, or indication of galling if the
trim has previously been in service. Do not lap for
shutoff any of the “P” series trims.
Assembly
1. With body in vise, place topworks yoke on bonnet
with yoke locknut slipped over the stem connector and
down on bonnet threads (6-9 PSIG air on air-to-open
topworks).
2. With topworks in correct position relative to the
centerline of the body, tighten yoke locknut using a
boxed-end (slotted) wrench.
FIG. 6
FIG. 7
3