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コントローラー CVS Controls 667のPDF 取扱説明書をオンラインで閲覧またはダウンロードできます。CVS Controls 667 8 ページ。 Diaphragm actuator

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Spring Adjustments cont'd

3. To shift the span up, turn the spring adjustor

(Key 11) into the yoke. To shift the span down,

turn the spring adjustor out of the yoke.

For operation of the CVS 667 Diaphragm Actuator

the actuator stem and valve plug stem must move

freely in response to the loading pressure change on

the diaphragm.

Maintenance

Actuator parts are subject to normal wear and tear

and should be inspected regularly. The frequency of

inspection and replacement of parts is dependent on

the severity of operating conditions.

WARNING

A sudden release of pressure or any

uncontrolled process fluid can cause

personal injury or damage to property. Prior

to any disassembly, be sure to:

•

Isolate the valve from the process,

•

Release all process pressure

•

Vent the actuator loading pressure, and

•

Relieve all spring compression.

Disassembly

Although the following instructions describe how the

CVS Type 667 Diaphragm Actuator can be

completely disassembled, when inspection or repairs

are required, only disassemble those parts required

to accomplish the job. Key numbers refer to Figures

4 and 5.

1. Bypass the control valve and reduce the loading

pressure to atmospheric.

2. Remove the tubing or piping from the connection

in the top of the yoke (Key 9). For top-loaded

construction also remove the piping or tubing

from the connection in the upper diaphragm

casing (Key 7).

3. Thread the spring adjustor (Key 2) off the stem

(Key 3) to remove all spring compression.

4. If necessary remove the actuator from the valve

body by separating the stem connector (Key 21)

and removing the yoke locknut.

5. Remove the spring adjustor (Key 2) from the

actuator stem (Key 3) and lift the spring seat and

spring (Keys 4 and 1) out of the yoke.

6. Remove the diaphragm casing cap screws and

nuts (Keys 10 and 14) and lift off the upper

diaphragm casing (Key 7).

7. Remove the following parts: diaphragm (Key 6),

diaphragm plate (Key 5), spacer (Key 32), cap

screw (Key 11) and actuator stem (Key 3). Be

careful not to damage the O-rings (Key 25) when

pulling the threads of the actuator stem through

the seal bushing (Key 24). Remove the stem

through the housing of the yoke so as not to pull

the threads through the seal bushing.

8. Separate the parts of this assembly by removing

the cap screw (Key 11).

9. To remove the seal bushing, remove the snap

ring (Key 30) and lift out the bushing.

10. Remove the cap screws (Key 19), the lower

diaphragm casing (Key 8) and the gasket (sizes

30 through 60) or O-ring (size 70) (Key 28).

11. If necessary, the down travel stops can be

removed (Key 33).

Assembly

1. Place a new gasket or O-ring (Key 28) on the

yoke (Key 9) and apply lubricant to the O-ring.

2. Position the lower diaphragm casing (Key 8) on

the yoke, align the holes and insert and tighten

the cap screws (Key 19).

3. If the down travel stops (Key 33) were removed,

insert and tighten them.

4. Coat the O-rings (Keys 28 and 29) with lubricant

and place them in the seal bushing (24).

5. Fill the seal bushing with lubricant, slide the

bushing into the yoke (Key 9) and install the

snap ring (Key 30).

6. Insert the actuator stem (Key 3) through the

spring housing of the yoke, then add the lower

diaphragm plate (Key 29), diaphragm (Key 6),

diaphragm plate (Key 5), and the travel stop cap

screw and spacer (Keys 11 and 32).

7. Place this assembly in the actuator, being careful

when pushing the actuator stem through the seal

bushing that the threads do not damage the O-

rings.

Note: Over tightening the diaphragm cap

screws and nuts can damage the diaphragm.

Do not exceed 20 foot-pounds (27 Newton

meters) torque.

8. Install the upper diaphragm casing (Key 7) and

secure with cap screws and nuts (Keys 10 and

14). Tighten evenly using a crisscross pattern to

ensure a proper seal.

9. Install the actuator spring (Key 1) and spring

seat (Key 4). Apply lubricant to the threads of

the actuator stem and to the surface of the

spring adjustor (Key 2) that contacts the spring

seat. Thread the spring adjustor onto the

actuator stem.

10. Mount the actuator onto the valve, following

procedures in the "Installation" section of this

manual.