Size 80 hydraulic snubber, Disassembly – Emerson Process Management 667 User Manual

Page 21

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Instruction Manual

D100311X012

667 Size 80 and 100 Actuators

May 2011

21

7. The lower sleeve (key 123) has two screw holes in one end. Coat the sleeve threads with lithium grease lubricant,

slide the end of the lower sleeve with the holes into the thrust bearing (key 43), turn the handwheel, and feed the
sleeve through the worm gear. Continue turning the handwheel until the lower sleeve protrudes from the gear
case. Fasten the travel stop indicator (key 126) to the sleeve with two machine screws (key 79).

8. Install the key (key 122) on the retaining flange (key 134).

9. Install the retaining flange (key 134) so that the key engages the slot in the lower sleeve. Secure the retaining

flange with the cap screws (key 136).

10. Adjust the set screws (key 121) to eliminate free play in the bearings.

Note

Overtightening the set screws will make handwheel operation difficult.

11. Coat the spring adjustor (key 74) threads with lithium grease lubricant and install it over the lower sleeve.

12. Pack the thrust bearing (key 86) with lithium grease lubricant, and install it on the spring adjustor (key 74) as

shown in figure 8.

13. Slide the spring case (key 85) into position, and secure with cap screws (key 88).

14. Complete steps 3 through 16 of the Assembly procedure in the Size 80 Actuator Maintenance section.

Size 80 Hydraulic Snubber

The size 80 667 actuator is available with a hydraulic snubber, as shown in figure 8, to aid vertical stability of the
actuator stem movement. The snubber is adjusted by rotating the adjusting screws (key 104, figure 8)
counterclockwise out of the reservoir (key 99, figure 8) to increase damping action and clockwise to decrease
damping action. The adjusting screw on the right (the top one of the two adjusting screws in section B‐B of figure 8)
regulates downward damping action, and the screw on the left regulates upward damping action.

Size 100 Top‐Mounted Handwheel (Adjustable Down Travel Stop)

Key numbers are shown in figure 9.

A top‐mounted handwheel assembly is normally used as an adjustable‐down travel stop to limit full extension of the
actuator stem. Counterclockwise rotation will compress the spring and move the actuator stem upward. Clockwise
rotation of the handwheel (key 58) allows spring action to return the actuator stem (key 144) downward.

Instructions are given below for complete disassembly and assembly. Disassemble only as far as necessary to
accomplish the required maintenance; then, begin the assembly at the appropriate step.

Disassembly

1. Isolate the control valve from the line pressure, release pressure from both sides of the valve, and drain the process

media from both sides of the valve. If using a power actuator, also shut off all pressure lines to the power actuator,
release all pressure from the actuator. Use lock‐out procedures to be sure that the above measures stay in effect
while you work on the equipment.

2. Bypass the control valve. Reduce the loading pressure to atmospheric (refer to the Maintenance section), and

remove the tubing or piping from the diaphragm casing.

3. Unscrew the cap screws (key 54), and remove the gear case cover (key 53).

4. Loosen the set screws (key 52) in the front and back worm retainers (keys 48 and 49) and the handwheel (key 58).

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