Emerson Fisher 667NS2 Instruction Manual page 22

667NS2 Actuator
March 2022
groove in the outer diameter of the seal bushing (key 116). Place the seal bushing and O­rings into the
spacer/diaphragm casing assembly (key 167) with the small diameter facing down, and install the snap ring (key
124) above the seal bushing (key 116).
13. To aid in assembly, attach the stem connector assembly (key 103) onto the actuator stem and grip the stem
connector in a vise. Coat the threads of the middle of the actuator stem (key 125) and seating side of the lower hex
jam nut (key 198) and upper hex jam nut (key 132) with Nuclear Grade anti-seize lubricant (key 27). Slide the lower
diaphragm plate (key 108), the diaphragm (key 105), and the upper diaphragm plate (key 107) onto the actuator
stem. Slide the first hex nut (key 198) onto the stem, tighten the hex nut to 650 N•m (480 ft•lbf), slide the second
hex nut (key 198) onto the stem, and tighten it to 407 N•m (300 ft•lbf). Thread the Loctite 242-applied cap screws
(key 197) into the lower hex jam nut (key 198), then tighten. Remove the subassembly from the vise, and remove
the stem connector assembly (key 103) from this subassembly.
14. Slide the threaded end of the actuator stem through the seal bushing (key 116) and the O­rings (key 117). Coat the
stem travel stop nut (key 168) with Nuclear Grade anti-seize lubricant (key 27). Slide it onto the actuator stem and
align its bolt hole with actuator stem set screw slot. Lubricate the set screw (key 170) with Loctite 242 (key 185).
Insert the set screw (key 170), and tighten.
15. Slide the threaded end of the actuator stem into the inner of the lower sleeve (key 163) until the stem travel stop
nut (key 168) contacts the lower sleeve (key 163) and rest the spacer/diaphragm casing assembly (key 167) on the
top flange of the gear case with the square boss on the spacer 180 degrees from the Fisher Logo of the yoke (key
109). Rotate the assembly to align the bolt holes in the spacer with the bolt holes in the top flange. Coat the threads
of cap screws (key 174) with Nuclear Grade anti-seize lubricant (key 27). Insert the cap screws and washers (keys
174 and 176) and tighten to 176 N•m (130 ft•lbf) torque using a criss-cross tightening pattern.
16. Rotate the assembly to align the bolt holes in the diaphragm (key 105) with the bolt holes in the lower diaphragm
casing.
17. Complete steps 5 through 15 of the Size 80 Actuator in the Assembly section.
18. Attach the two travel scales (key 113 and 183) to the yoke (key 109) using the pan head machine screws (key 126)
per scale. Leave the screws finger-tight; they will be tightened after adjustment of the travel scale.
19. Mount the two spacer cover bands (key 177) using hex cap screws (key 178); torque to 23 N•m (17 ft•lbf).
20. Install the fitting with the cap (key 184) into the gear case.
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Instruction Manual
D103472X012