Powers 593 Series Flowrite II Heavy Duty Bronze Globe Control Valves - Manual (Page 10)

10
REPLACING A DIAPHRAGM (REVERSE ACTING ACTUATORS)
The diaphragm can be changed with the actuator assembled or
removed from the valve. For ease of instruction pictures are shown
with actuators removed.
To change a diaphragm on a Reverse Acting (RA, NC, ATO)
actuator assemble to the valve follow steps: 1-4A, 5-10.
To change a diaphragm on a Reverse Acting (RA, NC, ATO)
actuator removed to the bench follow steps: 1-4A, 5-9.
To change a diaphragm of a Reverse Acting (RA, NC, ATO)
actuator assemble to the valve and under preload follow steps:
1-3, 4B, 5-10.
1. Shut off controlled medium supply (steam, water, or other
liquid) and remove the control signal to the actuator.
2. Reduce preload on the springs. Follow procedures for
Decreasing Preload on DA Actuators on pg. 7.
3. Remove the control signal to the actuator.
4A. (Fig 1) Remove top housing nuts and bolts or see above
4B. (Fig 1) Remove the three bolts attached to the short nuts, then
equally release the bolts attached to the long nuts.
CAUTION: Springs under tension.
5. Remove upper housing (Fig 2).
6. Remember the orientation of the springs. Remove springs, stem
nut...(Fig. 3).
7. ...silver washer, thrust plate, diaphragm, & black washer
(Fig. 4).
8. Replace with new diaphragm. Make sure the lip of the
diaphragm is seated properly in the groove of the actuator
housing.
8. Reassemble in reverse order.
NOTE: Assemble bolts with long nuts first.
10. Adjust preload, refer to pg. 7.
Fig 1 - Remove Housing Bolts Fig 2 - Remove Upper Housing, Remove
Springs (4 Shown)
Fig 3 - Remove Stem Nut... Fig 4 - Remove Thrust Plate and Old
Diaphragm