133 Series
7
4. Insert a 1/2-inch (12,7 mm) open-end wrench
between the legs of the cage (key 5) and place
the wrench on the stem sleeve wrench flats. Hold
this wrench while unscrewing the nut (key 31) to
prevent stem and stem sleeve (keys 18 and 25)
rotation and diaphragm damage due to twisting
(see Figure 4).
5. Remove the washer, registration disk, and valve
disk (keys 30, 29, and 28). To remove the restriction
collar (if used), loosen the set screw (key 47,
Figure 13) and slip the E-Ring (key 26) and collar
off of the stem. Remove the orifice (key 2) by
rotating it until the pins (key 5A) in the cage line up
with the slots in the orifice; then, lift off the orifice.
Replace the valve disk and orifice if necessary.
6. Loosen the set screws (key 39) in the cage and
remove the roll pin (key 27) from the stem.
Remove the cage and stem sleeve, the sealing
washer under the balancing diaphragm, flat
washers (key 23), balancing diaphragm, and
balancing diaphragm plate (key 21). Replace
sealing washer and balancing diaphragm
if necessary.
7. To inspect or replace the upper stem seal O-ring
or main diaphragm (key 15) on the Type 133L or
133H (Figure 10 or 11), remove the closing cap
(key 9), disengage the adjusting screw (key 11),
and remove the spring (key 12).
For Type 133Z (Figure 12), remove the closing cap
(key 9) and disengage the adjusting screw (key 11).
Lift the adjusting screw assembly (keys 11, 41,
42, 43, and 45) out of the spring case with pliers.
Unhook the extension spring (key 44) from the
spring retainer (key 42). Remove the compression
spring (key 12) if one is used.
8. Unscrew the cap screws and nuts (keys 35 and 36)
and remove the spring case.
9. Pull out the diaphragm and stem as assembly;
replace diaphragm and sealing washer (key 17)
if necessary. When removing or replacing the
diaphragm, clamp the smallest diameter portion if
the stem in a vise while turning the nut (key 20).
10. If necessary, replace the guide bushing (key 6)
and the upper stem seal O-ring (see Figure 5).
Before reassembling, coat the O-ring with
Bell-ray No. 80 or an equivalent O-ring sealant
and lubricant.
Reassembly
Reassemble in reverse order of the above steps. When
reassembling, observe the following steps and cautions.
1. If the spring case was disassembled, reassemble
it first. To ensure proper slack in the diaphragm
and to facilitate reassembly of the trim parts,
tighten the casing cap screws finger-tight only.
Then adjust the spring to stroke the diaphragm
assembly fully. Final tightening of the casing
cap screws and nuts must be done alternately in
equal increments to ensure a proper seal without
crushing the diaphragm.
2. During reassembly, check all O-rings to be
certain they are in good condition; replace if
necessary. Lubricate the O-rings (keys 4, 19,
and 32) with Dow Corning No. 3 or an equivalent
elastomer sealant and lubricant.
3. When installing the balancing diaphragm, be
certain the side marked PISTON SIDE is facing the
spring case. Carefully tuck the slack diaphragm
material into the space between the diaphragm plate
W1372/IL
Figure 5.
Inspecting Guide Bushing and Stem Seal O-Ring
W1371/IL
Figure 6.
Installing Balancing Diaphragm. The Side of
Diaphragm Marked Piston Side Must Face Casing.
