Leslie Controls CONTROL VALVES DLOS-2 & DDLOS-2 (150/300) - Manual (Page 7)

7
actuator over valve plug stem and bolts (9)
to top of packing bearing (12). Secure with
two nuts (7) finger tightened.
14.
Secure Actuator flange to bonnet flange with
Cap Screws.
15.
With wrench on flats of valve stem, lift
valve plug (2) and with counter-clockwise
motion engage threads in upper stem (31) of
actuator until valve plug can be turned no
more.
SETTING VALVE TRAVEL
CLASSES: DLO-2 AND DLOS DIRECT
ACTING ACTUATOR
(See Fig. 7 in Appendix)
1.
Connect controlled air line to diaphragm
case connector.
2.
Supply 3 PSIG air pressure to actuator
diaphragm.
3.
Compress actuator spring by turning spring
adjustor (35) until travel indicator (37) just
starts to move when air pressure is raised
above 3 PSIG.
NOTE: Alternately add compression and check
starting pressure slightly above 3 PSIG until
correct adjustment is attained. After each check
return air pressure to 3 PSIG.
4.
Actuator spring preload adjustment can be
made either with or without pressure in
valve body. Once correct compression is
made no further adjustment is necessary.
5.
With valve plug and coupling threads
engaged supply 20 PSIG operating pressure
to actuator diaphragm. Valve will move to
closed position. Observe travel obtained as
shown by travel indicator and indicator
scale. Read- just as follows:
6.
OVERTRAVEL – If travel is too great,
loosen stem locknut and turn valve plug
stem out of coupling the amount necessary
to obtain correct travel.
7.
UNDERTRAVEL – (Travel is too short)
This is not possible if prior step 15 was done
and correct parts were used.
8.
When correct travel has been obtained
reduce operating pressure sufficiently to
move valve plug away from seat ring. Then
turn valve stem one full turn out of upper
stem threads. Secure locknut.
9.
The one full turn toward the seat ring, made
after obtaining travel, provides the positive
closing force required to obtain tight valve
closure. In all cases be sure to make this
final adjustment.
10.
Tighten locknut. Reconnect operating
medium tubing from the sensing element or
manual loading device to the diaphragm
case.
SETTING VALVE TRAVEL
CLASSES: DDLO & DDLOS REVERSE
ACTING ACTUATOR
(See Fig. 9 in Appendix)
1.
Connect controlled air line to diaphragm
case connection.
2.
Supply 3 PSIG air pressure to actuator
diaphragm.
3.
Compress actuator spring until travel
indicator begins to move when air pressure
is raised above 3 PSIG.
NOTE: Alternately add compression and check
starting pressure slightly above 3 PSIG until
correct adjustment is attained. After each check
return air pressure to 3 PSIG.
4.
The valve plug is closed against upward
fluid thrust by actuator spring force. Total
compression placed on actuator spring must
be sufficient to provide the 3 PSIG preload
plug force required to close the valve.
5.
If preload adjustment is made with no
pressure in valve body, then, when the
control valve is placed in operation,
additional compression must be placed on
the actuator spring to provide valve closure
force. With proper adjustment valve will