Leslie Controls DOT 3-WAY CONTROL VALVE - Manual (Page 6)

6
1. DIRECT ACTING
DISMANTLING SIZES 35, 55, 55A, 85
Remove bolts/nuts, upper diaphragm case and old
diaphragm.
To examine, clean or replace other internal components lift
out diaphragm plate assembled with actuator stem,
actuator spring, washer and unscrew spring adjustor from
adjustor sleeve.
REASSEMBLY
Replace internal parts. Install new diaphragm. In sizes 35,
55, 55A and 85 line up holes with those in lower
diaphragm case. Replace upper diaphragm case on
diaphragm. Assemble four bolts and nuts through parts
(90º apart). Fingertighten. Assemble balance of bolts/nuts
to actuator. Tighten evenly and alternately across
diaphragm case. (Before tightening bolts in 35 actuators or
where flat stock diaphragm material is used in other sizes
as an emergency measure) consult note relating to
performing actuator diaphragm.
2. REVERSE ACTING
DISMANTLING SIZES 35R, 55R, 55AR, 85R (See
Figure 5)
Remove bolts/nuts and upper diaphragm case. Insert rod
through holes in yoke and actuator stem to prevent twisting
of stem seal when removing self-locking nut. (In size 35R
use wrench on flats on actuator stem) Remove self-locking
nut, stem seal. Remove stem seal as follows: In 35R
remove stud nuts and disassemble lower diaphragm base
from yoke. Lift out stem seal. In 55R and 85R DO NOT
remove lower diaphragm base unless gasket is to be
replaced. Stem seal is held in place by seal ring and
screws. Take out these parts and lift out stem seal.
NOTE: To check actuator spring and other components. In
35R, 55R and 85R parts are taken out from the underside.
REASSEMLBY
Reassemble spring adjustor, washer, actuator spring, and
top spring seat to actuator stem (if they have been
removed.) Replace assembled parts in yoke. Place stem
seal collar on actuator stem. Position stem seal on stem
collar. In sizes 55R and 85R place bead of stem seal in
recess of stem seal collar.
In 35R reassemble lower diaphragm base to yoke. Insert
capscrews through holes in lower diaphragm case and
diaphragm and into threads in yoke. Tighten after resetting
stem seal as described below.
In 55R and 85R actuators replace sealing ring and screws.
Tighten.
PRE-SETTING STEM SEAL – (55R AND 85R)
Place collar on stem seal, making sure that bead on stem
seal enters recess in collar. Reassemble diaphragm over
actuator stem. Fit center hole in diaphragm around raised
face of collar. Replace diaphragm plate and self locking
nut. Hold actuator stem steady with rod through yoke and
stem (35R) then tighten self-locking nut. Replace upper
diaphragm case and bolts/nuts. Tighten as described
previously.
PRE-SETTING STEM SEAL – (35R)
Place collar on stem seal, assemble self-locking nut to
actuator stem and tighten down against parts. Then press
actuator stem downward to make stem seal move to taut
position. Tighten capscrews and remove self-locking nut.
3. MOUNTING ACTUATOR TO MAIN
BODY
Set preload on actuator spring, reassemble actuator to
valve body assembly, if it had been removed, adjust valve
for rated travel and reconnect operating medium tubing.
SOME IMPORTANT NOTES
FLAT SHEET RUBBER MATERIAL
Flat sheet rubber materials may be used in 55(R) and
85(R) actuators as emergency replacement material,
but for guaranteed results it should be replaced at the
earliest opportunity with the Leslie Rolling Action
Diaphragm designed specifically for these actuators.
When flat material is used in emergency perform as
described below.
PERFORMING 35(R) ACTUATOR DIAPHRAGMS
Flat stock material is used for diaphragms in 35(R)
actuators. When assembling first fingertighten all
diaphragm case bolts. Then compress actuator spring
sufficiently to move diaphragm through full travel to
upper or lower diaphragm case depending on whether
actuator is direct or reverse acting. This performs
diaphragm and permits full movement through rated
travel without resistance from a taut diaphragm.