Emerson Process Management 667 - Manual (Page 16)

Instruction Manual
D100311X012
667 Size 80 and 100 Actuators
May 2011
16
6. Install the diaphragm backup plate, diaphragm retainer, diaphragm, upper diaphragm plate, and washer (keys 6, 5,
3, 4, and 37) on the actuator stem (key 144).
CAUTION
Install the diaphragm with the fabric side facing away from the spring. Smooth the edge of the diaphragm to avoid
wrinkling and be careful that the diaphragm fold does not get pinched when the upper diaphragm casing (key 1) is
installed.
CAUTION
If the diaphragm (key 3) is installed so air pressure is applied to the fabric side, it will immediately delaminate the sealing
surface (smooth surface) from the fabric. The delamination can cause immediate failure of the diaphragm's ability to retain
pressure.
7. For actuators with a top‐mounted handwheel, screw the actuator stem extension (key 36, figure 9) as far as it will
go into the actuator stem connector (key 42, figure 9) before tightening the hex nut (key 28, figure 9).
8. For actuators without a top‐mounted handwheel, Install the hex nut (key 241) and tighten, install the jam nut (key
24) and tighten so that it locks the hex nut key 24 in place. Install the travel stop (key 12).
9. Position the upper diaphragm casing (key 1) on the diaphragm (key 3) and align the holes.
Note
When you replace actuator diaphragms in the field, take care to ensure the diaphragm casing cap screws are tightened to the
proper load to prevent leakage, but not crush the material. Perform the following tightening sequence with a manual torque
wrench for size 80 and 100 actuators.
CAUTION
Do not use lubricant on these cap screws and nuts. Fasteners must be clean and dry.
Overtightening the diaphragm casing cap screws and nuts can damage the diaphragm. Do not exceed 68 N Sm (50 lbfSft)
torque.
10. Insert the cap screws (key 13) into the upper diaphragm casing, and tighten the hex nuts (key 14) in the following
manner. The first four hex nuts tightened should be diametrically opposed and 90 degrees apart. Tighten these four
hex nuts to 34 N
Sm (25 lbfSft).
11. Tighten the remaining hex nuts in a clockwise, crisscross pattern to 34 N Sm (25 lbfSft).
12. Repeat this procedure by tightening the four hex nuts, diametrically opposed and 90 degrees apart, to a torque of
68 N Sm (50 lbfSft).
13. Tighten the remaining hex nuts in a clockwise, crisscross pattern to 68 N Sm (50 lbfSft).
14. After the last hex nut is tightened to 68 N Sm (50 lbfSft), all of the hex nuts should be tightened again to 68 NSm
(50 lbf Sft) in a circular pattern around the bolt circle.