Instruction Manual
D100381X012
HS Valve
June 2019
13
Mounting Actuator and Adjusting Travel
Direct-Acting Valves
(Push-Down-to-Close)
1. If the actuator and valve have been separated, mount the actuator and secure with the yoke locknut (valves with
3/8, 1/2, or 3/4-inch stems) or eight cap screws and nuts (valves with 1 or 1-1/4 inch stems).
2. Move the valve plug to the closed position.
3. Screw two locknuts all the way onto the valve plug stem thread. Set the travel indicator disk on these nuts with the
concave side of the disk facing the valve. On some larger actuator sizes, a pointer attached to the stem connector is
used instead of the travel indicator disk.
WARNING
To avoid personal injury, keep hands and tools away from the actuator stem when pressuring the actuator
.
4. If the actuator stem is not fully extended, pressure the actuator to move the stem to the fully extended position.
Retract the actuator stem approximately 1/8 inch by reducing actuator pressure. (This requires pressuring the
actuator for reverse-acting diaphragm actuators and piston actuators).
5. Clamp the actuator stem to the valve stem with the stem connector. Raise the indicator disk to the stem connector
and tighten in position with the stem locknuts.
6. Cycle the actuator to be sure that full travel is being obtained and that the valve plug seats before the travel stop (if
one is present) is contacted.
CAUTION
Do not use wrenches or other tools directly on the valve plug stem, or damage to the stem surface and subsequent damage
to the valve packing may result. Never rotate the valve plug stem while the valve plug is in contact with the valve seat ring,
or damage to the valve seating surfaces may result. Be certain the plug is off the seat before rotating the stem.
Minor travel adjustments can be made by loosening the stem connector slightly, tightening the locknuts together,
and screwing the stem into or out of the stem connector by using a wrench on the locknuts. If an increase in travel is
desired, the increase must be less than the 1/8 inch the actuator stem was retracted in step 4, or the valve will not shut
off.
7.
A
fter adjustments are complete, tighten the stem connector securely, lock the travel indicator disk against the
connector with the locknuts, and adjust the travel indicator scale to show valve plug position.
8. Final adjustments to establish the starting point of valve travel (zero) and to obtain full travel for the given signal
range (span) can be made to the actuator spring or valve positioner. Refer to the appropriate actuator or valve
positioner instruction manual for instructions.
