ML6984, ML7984 SERIES 4000 DIRECT COUPLED VALVE ACTUATORS
3. Remove stem button (Fig. 3) from valve stem.
4. (Optional) Snap red position indicator (metal clip) over
valve stem and position for best visibility (Fig. 3). Indica-
tor will self-align to the marking on yoke after complete
operating cycle. It is recommended that this is done after
actuator installation.
Remove Stem Button
NOTE: DO NOT
DAMAGE ANY
Valve Stem
PART OF
THE STEM.
ASSEMBLY OF POSITION INDICATOR
1 Position indicator will fit 1/4 in. - 7-1/16 in. valves.
Fig. 3. Preparation for Valve Assembly.
Assembly of MLx984 Actuator to the
Valve
1. The drive shaft of the MLx984 Actuator has a 1/4-28
UNF threaded hole to link with the valve stem. Slide the
yoke over the valve bonnet (Fig. 4).
2. Thread the MLx984 Actuator drive shaft onto the valve
stem all the way, until it is completely attached (with no
threads showing), by turning the valve actuator in a
clockwise direction, as viewed from above. Depending
on the valve body, use a pin or wrench to keep the valve
stem from turning. Note that the valve actuator is
shipped with the drive shaft in the mid-position.
3. Care should be exercised when using tools on the valve
stem during tightening (Fig. 4). DO NOT damage the
threads or other parts of the stem.
4. Orient the conduit hole to the most desirable direction,
then tighten the LOCKNUTS on the U-bolt.
5. Remove the plastic cover from the MLx984 by loosening
the two captive screws located on the top. Drop the Allen
(Hex) type of set screw (included in the plastic bag) into
the top of the shaft, hex side up.
6. Tighten the set screw to lock valve stem in place
(Fig. 6), using a 1/8 in. Allen wrench (included).
Fig. 4. U-bolt Assembly.
95C-10939EFS—03
NOTE: Use the U-bolt supplied with the actuator. Do not
replace with stainless steel U-bolt on chilled water
valves. Condensation may cause corrosion of yoke
with SS U-bolt.
Valve Stem
Position
1
Indicator
(Metal clip)
Yoke
M25487
Fig. 6. Locking MLx984A Drive Shaft to Valve Stem.
CAUTION
For proper valve operation the valve stem must be
M25488
threaded into the actuator all the way (with no
threads showing) and locked in place with the set
screw provided.
4
DO NOT
ADJUST
Valve Bonnet
U-bolt
2
THREAD ACTUATOR SHAFT TO VALVE STEM BY
1
ROTATING IN A CLOCKWISE DIRECTION.
2
TIGHTEN U-BOLT NUTS TO SECURE LINKAGE TO
VALVE BODY.
Fig. 5. Assembly of MLx984A to Valve.
5mm [3/16 in.] Slotted Screwdriver
or Allen Wrench
Set Screw
1
Yoke
M25489
Linkage
Valve Stem
M25490