Dwyer LIN-E-AIRE® - Manual (Page 8)

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4. MAINTENANCE
4.1 Test Equipment and Tools Required - The only test equip-
ment required for valve and actuator maintenance is an air sup-
ply source, gage and regulator. The tools required are shown in
Table 4.
4.2 Adjusting Valve Plug Travel - The purpose of this proce-
dure is to adjust the length of valve stem engagement in the push
rod so that the travel indicator is at the travel marks on the indi-
cator plate when valve is fully closed.
4.2.1 Push-to-Close Valve with Air-to-Lower Actuator
1. Apply air pressure to actuator to fully close valve and note
location of travel indicator.
2. If indicator is not at travel marks on plate, Figure 5, measure
distance between indicator and mark.
CAUTION: Do not make any adjustments when valve plug is on
its seat.
3. Vent all pressure from actuator.
4. Loosen stem locknut, Figure 7. Grip valve stem near threads,
and turn stem to move valve plug the distance measured in Step
2.
5. Position indicator toward travel indicator plate and tighten
valve stem locknut.
6. Repeat Steps 1 thru 5 until travel indicator is at travel marks
when valve is fully closed.
Note: If pressure range required to obtain full valve plug travel
does not agree with range stamped on data plate, refer to 3.2
Adjusting Actuator Range.
4.2.2 Push-to-Close Valve with Air-to-Raise Actuator or
Push-to-Open Valve with Air-to-Lower Actuator
1. Apply air pressure to actuator to fully open valve and note loca-
tion of travel indicator.
2. If indicator is not at travel marks on plate, Figure 5, measure
distance between indicator and mark.
CAUTION: Do not make any adjustment when valve plug is on
its seat.
3. Loosen stem locknut, Figure 7. Grip valve stem near threads,
and turn stem to move valve plug the distance measured in Step
2.
4. Position indicator toward travel indicator plate and tighten
valve stem locknut.
5. Vent all pressure from actuator.
6. Repeat Step 1 thru 5 until travel indicator is at travel marks
when valve is fully opened.
Note: If pressure range required to obtain full valve plug travel
does not agree with range stamped on data plate, refer to 3.2
Adjusting Actuator Range.
4.3 Replacing Actuator Diaphragm
WARNING: Before attempting any maintenance on control valve,
make sure valve has been relieved of all pressure.
4.3.1 Air-to-Lower Actuator
1. Isolates or bypass the control valve in pipe line.
2. Shut off pressure to actuator and disconnect air line.
3. Turn range spring adjusting screw counter-clockwise to relieve
all spring compression.
WARNING: If all spring compression is not relieved, serious injury
can occur when removing upper diaphragm casing.
4. Loosen and remove all diaphragm casing mounting bolts, nuts
and washer, Figure 8.
5. Lift off upper diaphragm casing from actuator assembly.
6. Remove old diaphragm and discard.
7. Install upper diaphragm casing with new diaphragm on actua-
tor assembly. Fasten with bolts, nuts and washers removed in
Step 4.
8. Reconnect pipe or tubing to pressure connection in upper
diaphragm casing.
9. Readjust actuator travel, refer to 3.2 Adjusting Actuator Range.
Figure 7. Adjusting Valve Plug Travel
Use
Travel Indicator Plate
Diaphragm Casing
Mounting Screw & Nut
Range Spring
Adjusting Screw
Actuator Push Rod
Table 4. Tools Required
Size
3/16 in.
1/4 in.
1/2 in.
9/16 in.
5/8 in.
7/8 in.
1-1/4 in.
1-1/2 in.
1-15/16 in.
9/16 in.
11/16 in.
13/16 in.
31/32 in.
1 in.
Tool
Screwdriver
Open End
Wrenches
Actuator
Size
All
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