Size 80 Actuators - Emerson Fisher 667NS Instruction Manual

Diaphragm actuators size 40, 45, 70, and 80

Table of Contents

Instruction Manual

D102603X012

6. Install three new O‐rings (keys 8 and 9) on the seal bushing.

7. Lubricate the O‐rings, and fill the seal bushing with lithium grease (key 99) or high‐temperature, radiation‐resistant,

polyphenyl ether grease (key 100), as appropriate to the installation and install the bushing in the top of the

actuator yoke assembly (key 73). Secure with the snap ring.

8. Coat a new gasket (key 70) with lithium grease (key 99) or high‐temperature, radiation‐resistant, polyphenyl ether

grease (key 100), as appropriate to the installation, and place the gasket on the yoke (key 73). Assemble the lower

diaphragm plate, the new diaphragm, and the upper diaphragm plate onto the actuator stem.

CAUTION

Do not allow the valve stem to rotate during this operation because it could cause damage to the valve seats.

9. Install the diaphragm plate cap screw and spacer. Tighten the cap screw to the torque value indicated in table 3. For

actuator sizes 40 and 45, place a wrench on the actuator valve stem connector assembly to prevent the actuator

stem from rotating during the tightening of the diaphragm plate cap screw.

Note

When you replace actuator diaphragms in the field, take care to ensure the diaphragm casing bolts 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 40, 45, and 70 actuators.

CAUTION

Overtightening the diaphragm casing cap screws and nuts (keys 13 and 14) can damage the diaphragm. Do not exceed a

torque of 27 NSm (20 lbfSft) when performing the following tightening procedure.

Note

Do not use lubricant on these cap screws and nuts. Fasteners must be clean and dry.

10. Place the upper diaphragm casing into position, and replace the diaphragm casing cap screws and nuts. 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 13 NSm (10 lbfSft).

11. Tighten the remaining hex nuts in a clockwise, criss‐cross pattern to 13 NSm (10 lbfSft).

12. Repeat this procedure by tightening four hex nuts, diametrically opposed and 90 degrees apart, to a torque of 27

NSm (20 lbfSft).

13. Tighten the remaining hex nuts in a clockwise, criss‐cross pattern to 27 NSm (20 lbfSft).

14. After the last hex nut is tightened to 27 NSm (20 lbfSft), all of the hex nuts should be tightened again to 27 NSm (20

lbfSft) in a circular pattern around the bolt circle.

15. Once completed, no more tightening is recommended.