Emerson Process Management 667 - Manual (Page 18)

Instruction Manual
D100311X012
667 Size 80 and 100 Actuators
May 2011
18
3. Install the actuator stem assembly into the yoke assembly (key 67). Place a support under the stem to position the
lower end of the stem 254 mm (10 inches) above the bottom surface of the actuator (actuator‐to‐bonnet joint).
Note
When installing the lower diaphragm casing, install O‐rings (key 70) into grooves found in the lower diaphragm casing before
placing the casing on the yoke assembly. If the spring interferes with installation of the lower diaphragm casing, reposition the
spring by rotating the adjusting nut.
4. Install the lower diaphragm casing (key 67), and secure it by tightening the four hex nuts.
5. Lubricate the seal bushing O‐rings (keys 8 and 9) and the seal bushing (key 7) with lithium grease lubricant. Install
the seal bushing O‐rings, seal bushing (keys 8 and 9), and seal bushing retainer (key 7) and secure with four hex
nuts.
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 diaphragm adaptor (key 245, figure 5) 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.
6. Install the diaphragm backup plate, diaphragm retainer, diaphragm, O‐ring, and diaphragm plate (keys 6, 5, 3, 240,
and 4) on the actuator stem (key 144).
7. Carefully fold the diaphragm between the diaphragm backup plate (key 246) and the case adapter (key 245) while
lowering the adapter onto the lower diaphragm casing assembly (key 67). Install all 40 cap screws (key 13) and
finger tighten.
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 cap screws (key 13) can damage the diaphragm. Do not exceed 68 N Sm (50 lbfSft) torque.