Leslie Controls DKLO D1 & D4 .5-4 125/250 class - Manual (Page 7)

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machined flats of actuator stem, and remove stem nut (10),
seal washer (12) and stem washer (11). Remove o-ring (8)
from bushing and replace if necessary. Lubricate o-ring
after installing.
RE-ASSEMBLY OF ACTUATOR
Refer to Figure 6 for correct orientation of casings,
diaphragm (15), piston (13), stem (16) and springs (3) for
direct or reverse action. Be sure piston spring recesses line
up between casing ribs as shown in Figure 8C. Lubricate
bushing O-ring (8) and insert actuator stem through
bushing. Re-attach upper casing (2) with long bolts (14) &
nuts (5), tightening alternately. Install remaining casing
nuts and bolts. Apply air to diaphragm case and check for
leakage, full travel and dead band less than .2 psi.
LAPPING PLUG INTO SEAT
Seats and plugs should never require more than the lightest
touch up with very fine (400 grit) grinding compound.
Heavy lapping will produce galling, a wider seating
surface and a groove in the plug, all of which tend to cause
leakage. Reface a damaged surface before attempting to
grind it in. Lap sparingly. Replace stem and plug (39) in
bonnet (25) through packing. Apply lapping compound to
plug. Place bonnet and bonnet flange (35 for D4 only) on
body. After lapping, disassemble and clean and parts
thoroughly.
PACKING REPLACEMENT
Check stem for marks and scratches if packing leaks.
Replacement packing cartridges can be installed.
RE-ASSEMBLY OF VALVE BODY (D1)
Tighten bonnet (25) to body. Replace yoke (9), lock nut
(26), stem nuts (24) and travel indicator (32) over stem
(34).
RE-ASSEMBLY OF VAVLE BODY (D4)
Install a new gasket (36). Attach bonnet (26) and bonnet
flange (35) to body with bonnet studs and nuts (33, 34). Be
sure to tighten bolts alternately and evenly to ensure proper
seating of the plug. Replace yoke (9), lock nut (27), stem
nuts (31) and travel indicator (23) over stem (30).
REPLACING ACTUATOR ON VALVE
BODY-PNEUMATIC
Put actuator assembly over valve stem. Place lock nut (Fig.
2, #26), and stem nuts (24) with travel indicator (32) on
valve stem. Rest actuator stem (16) on valve stem. Tighten
stem nuts approximately 2/3 down valve stem. Lift
actuator assembly and engage valve stem with actuator
stem (be careful not to gall plug & seat).
REVERSE ACTING
When sufficient engagement is met, the actuator can be
energized with air to place the yoke on the bonnet (25) and
lift the plug off the seat. Tighten lock nut and packing nut.
DIRECT ACTING
Engage valve stem with actuator stem so no contact is
made between plug and seat when bottom of yoke is rested
on bonnet. Tighten lock nut.
ACTUATOR ADJUSTMENT – PNEUMATIC
Close inlet and outlet stop valves. Be sure valve body is
not under pressure. Place a wrench on the machined flats
of actuator stem (16). Counter two stem nuts (24)
approximately halfway down the threads of the stem (34).
REVERSE ACTING
Apply sufficient air pressure to diaphragm case to start
moving valve through its rated travel. This is shown by
travel indicator (32). Engage lower stem nut (24) and turn
body stem (34) into actuator stem (16) until pre-
compression of actuator springs (3) is relieved (plug
should not be seating on seat ring when air pressure is
removed from actuator case). Apply prescribed setting
pressure to actuator. This is determined by specific
operating conditions. Turn body stem out of actuator stem
until plug seats on seat ring (28). To prevent galling, do
not turn body stem after plug has contacted seat ring. Turn
stem nuts up plug & stem assembly and tighten to lock
them in position. Reduce air signal to 0 psi and calibrate
indicator scale (20). Check that full travel is achieved with
a 15 psi signal.
DIRECT ACTING
Engage lower stem nut (24) and turn body stem (34) into
actuator stem (16) until plug & stem assembly stops at
upper limit of travel and/or a slight downward movement
of actuator stem is detected. Turn stem nuts up body stem
and tighten them to lock in position. Calibrate indicator
scale (20). Check that full travel is achieved at a 3 psi
signal.