Powers 593 Series Flowrite II Heavy Duty Bronze Globe Control Valves - Manual (Page 7)

CHANGING ACTION (REVERSE ACTING ACTUATORS)
Change Actuator Action from RA to DA:
1. Shut off controlled medium supply (steam, water, or other
liquid).
2. Reduce preload on the springs (refer to Decreasing Preload
on RA Actuators).
3. Remove the control signal to the actuator.
4. (Fig. 1) Use a 1/2" wrench on the top housing bolts and hold
the bottom housing nuts with a 9/16" wrench.
5. (Fig. 2A) Remove upper housing.
6. Remember the orientation of springs on the thrust plate.
Remove springs, stem nut (Fig. 2B)...
7. …silver washer, thrust plate, diaphragm, & black washer
(Fig. 2C).
8. Hold the actuator stem in place and loosen the valve stem
locknuts (turn locknut counterclockwise a number of times).
9. Hold actuator stem and tighten the two lock nuts together.
Turn the locknuts counterclockwise to rotate the valve stem
until the two stems are separated. (Fig. 3)
10. Pull actuator stem upward and remove from assembly.
(Fig. 4).
11. Replace with DA actuator stem. Position stem with flats
pointing downward.
12. Thread valve stem into actuator stem by turning the locknut
clockwise. Tighten by hand.
13. Place springs in lower housing in same orientation as found
on thrust plate. Properly seat springs over the spring guides
14. Invert thrust plate and place on top of springs. Invert
diaphragm and place on top of thrust plate (Fig. 5).
15. Replace black washer, place silver washer on top of black
washer, and tighten stem nut (Fig. 6).
16. Replace upper housing assembly and tighten housing nuts
and bolts (Fig. 1).
17. Connect control signal to 1/4" NPT fitting located on the
top of the actuator housing.
18. Adjust the preload per instructions on pg. 7.
Fig 1 - Remove Housing Bolts Fig 2A - Remove Upper
Housing to Expose Springs
(4 Shown) Fig 2B - Remove Springs,
Stem Nut
Fig 3 - Loosen Stem Locknuts Fig 4 - Remove and Replace
Stem Fig 5 - Replace Springs,
Reversed Thrust Plate and
Diaphragm
Fig 2C - Remove Washers,
Thrust Plate, Diaphragm
Fig 6 - Replace Washers,
Tighten Stem Nut
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