Powers 593 Series Flowrite II Heavy Duty Bronze Globe Control Valves - Manual (Page 9)

9
REPLACING A DIAPHRAGM (DIRECT 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 Direct Acting (DA, NO, ATC)
actuator assemble to the valve follow steps: 1-4A, 5-9.
To change a diaphragm on a Direct Acting (DA, NO, ATC)
actuator removed to the bench follow steps: 1-4A, 5-8.
To change a diaphragm of a Direct Acting (DA, NO, ATC)
actuator assemble to the valve and under preload follow steps:
1-3, 4B, 5-9.
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 (refer to Decreasing Preload on
DA Actuators), see pg. 7.
3. Remove the control signal from 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. Remove stem nut, washer and diaphragm. (Fig. 3)
7. Place new diaphragm over thrust plate. Make sure that 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.
9. Adjust preload, refer to pg. 7.
Fig 1 - Remove Housing Bolts Fig 2 - Remove Stem Nut, and
Washers Fig 3 - Remove Diaphragm (Leave
Thrust Plate On).