Emerson Fisher 667NS Instruction Manual page 17

Instruction Manual
D102603X012
CAUTION
Overtightening the diaphragm casing cap screws and nuts can damage the diaphragm. Do not exceed the following
maximum torque values for the appropriate diaphragm material: EPDM/Meta-Aramid: 95 NSm (70 lbfSft);
Nitrile, Silicone, FKM (fluorocarbon) / Meta-Aramid: 68 NSm (50 lbfSft).
Note
Do not use lubricant on these cap screws and nuts. Fasteners must be clean and dry.
9. Insert the diaphragm casing cap screws and nuts (keys 13 and 14) and tighten in the following manner. The first
four hex nuts tightened should be diametrically opposed and 90 degrees apart. Tighten these four hex nuts to the
initial torque value found in table 6 for the diaphragm material being used.
10. Tighten the remaining hex nuts in a clockwise, crisscross pattern to the initial torque value found in table 6 for the
diaphragm material being used.
11. Repeat this procedure by tightening four hex nuts, diametrically opposed and 90 degrees apart, to the final torque
value that is specified in table 6 for the diaphragm material being used.
12. Tighten the remaining hex nuts in a clockwise, crisscross pattern to the final torque value that is specified in table 6
for the diaphragm material being used.
13. After the last hex nut is tightened, complete another tightening sequence. Tighten in a circular pattern around the
bolt circle to the final torque value that is specified in table 6 for the diaphragm material being used.
14. Once completed, no more tightening is recommended.
15. Lubricate the spring adjustor (key 74) threads and the bearing race and bearing with lithium grease. Thread the
spring adjustor (key 74) into the spring case assembly so that the spring adjustor matches the position recorded in
step 2 of the disassembly procedures for size 80 actuators. Also, make sure that the spring adjustor properly
engages the spring seat.
16. Turn the spring adjustor hex nut (key 90) tightly against the spring case.
17. Lubricate the bearing race and bearing with lithium grease, and slide them over the actuator stem into the spring
adjustor. Insert the bearing retainer snap ring (key 87) into the spring adjustor. Thread the two hex nuts (keys 85
and 86) onto the actuator stem. If the hex nuts (keys 85 and 86) are not used as a travel stop, thread them onto the
actuator stem until they touch the spring adjustor. Back them off approximately 3.2 mm (1/8‐inch), and lock them
together. If these hex nuts (keys 85 and 86) are used as a travel stop, thread them onto the actuator stem so that
they do not restrict actuator travel during travel adjustment. Adjust the hex nuts as outlined in the Actuator
Mounting section.
18. Screw the two hex nuts (key 69) onto the valve plug stem. Mount the actuator on the valve body, and make the
stem connection by following the procedures in the Actuator Mounting section.
667NS Actuator
June 2018
17