Instruction Manual
D103793X012
585CLS Actuator
October 2013
6
Three-Way Valve Applications Note
WARNING
To avoid loss of control of process fluid and subsequent personal injury or property damage caused by bursting of
pressure-retaining parts, be sure the cylinder pressure does not exceed 80 psig in high cycle-rate, fast stroking speed,
three-way valve applications.
In three-way valve applications where the actuator fully strokes at a frequency of once per minute or faster, and the
stroking speed is rapid (less than 0.5 seconds per stroke), there is a possibility that the stem can fracture at the plug if
the actuator cylinder pressure is greater than 80 psig. This can cause loss of control of process fluid and further
damage to the actuator. Consideration should be given to the use of high-strength, fatigue-resistant stem materials in
these applications.
Actuator Mounting
The following procedure describes how to mount a 585CLS actuator on a push-down-to-close valve so that the piston
stem to valve plug stem connection allows full travel and proper shutoff. Key numbers referenced in the following
steps are shown in figures 2 and 3.
If you purchase a 585CLS actuator for field installation on a control valve, mount the actuator on the valve and secure it
to the bonnet with the eight bonnet-to-actuator bolts. The stem connection should then be made up to clamp the
actuator stem and valve plug stem together to provide proper valve travel.
CAUTION
To avoid damaging the seating surfaces, do not rotate the valve plug while it is seated. Avoid damage to the valve plug
stem by careful use of tools during travel adjustments.
1. With the valve assembled and actuator mounted, make sure the valve plug is in the closed position. Then turn the
two stem locknuts (key 23) all the way onto the stem thread.
2. Starting with the cylinder fully retracted, manually or with air pressure extend the piston rod extension the specified
valve travel.
3. Attach the stem connector (key 22), clamping the piston rod extension to the valve stem. Be sure you also attach
the feedback arm (key 4) and travel indicator (key 3).
4. Cycle the actuator to check availability of desired total travel and that the valve plug seats before the cylinder
reaches the end of its stroke. You can make minor travel adjustments, if necessary, by loosening the stem
connector slightly, tightening the locknuts together, and (with the valve plug off the seat) screwing the stem either
into or out of the stem connector by means of a wrench on the locknuts.
5. If the total travel is adequate, tighten the stem connector (key 22) securely, lock the stem locknuts (key 23) against
the connector, and adjust the indicator scale (key 7) on the yoke (key 1) to show valve plug position.
6. Provide a gauge, if necessary, to measure the pressure to the actuator. Make a final adjustment on the positioner to
set the starting point of valve travel and to obtain full travel for the given instrument range.
Handwheels
Key numbers referenced in the following steps are shown in figures 2 and 3.
