GE Masoneilan 4700E, Maintenance Manual

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4. Select the desired cam lobe and replace cam (26) on cam shaft with low signal line
of desired lobe against cam follower. Ensure that the newly selected cam lobe is in
the same relative position as the lobe in Step 3.
5. Replace washer (27) and screw (28). Reduce pressure applied in Step 2 to zero
(back off the handwheel if handwheel was used). Disconnect the independent
regulated air line to actuator and connect positioner output line. Connect supply
pressure and signal to positioner. Check zero and span adjustment. Refer to “Zero
Adjustment” on page 48 and “Span Adjustment” on page 48.
Air to Close / Direct Acting Positioner
See Figure 19 on page 68 and Figure 20 on page 71.
1. 1. Shut off supply pressure and signal to positioner. Valve is now open and cam
(26) is at low signal line on lobe.
2. With cam at low signal line remove screw (28) and washer (27). Note the relative
position of the cam lobe being changed and then remove the cam (26).
3. Select the desired cam lobe and replace cam (26) on cam shaft with low signal line
of desired lobe against cam follower. Ensure the newly selected cam lobe is in the
same relative position as the lobe noted in Step 2.
4. Replace washer (27) and screw (28). Check zero and span adjustment. Refer to
“Zero Adjustment” on page 48 and “Span Adjustment” on page 48.
Air to Close / Reverse Acting Positioner
See Figure 19 on page 68.
1. Shut off supply pressure and signal to positioner. Valve is now open and cam (26) is
at high signal line on lobe. Do not remove.
2. Run an independent regulated air line to the valve actuator in place of positioner
output line. Slowly apply proper air pressure through the regulator to shut the
valve. Do not exceed designated supply pressure. (Handwheel may be used to
close the valve in place of regulated air line.) Align the travel indicator with the
closed end of travel scale. Cam is now at low signal line on lobe.
3. With cam at low signal line remove screw (28) and washer (27). Note the relative
position of the cam lobe being changed and then remove the cam (26).
4. Select the desired cam lobe and replace cam (26) on cam shaft with low signal line
of desired lobe against cam follower (4A). Ensure the newly selected cam lobe is in
the same relative position as the lobe noted in Step 3.
5. Replace washer (27) and screw (28). Reduce pressure applied in Step 2 to zero
(back off the handwheel if handwheel was used). Disconnect the independent
regulated air line to actuator and connect positioner output line. Connect supply
pressure and signal to positioner. Check zero and span adjustment. Refer to “Zero
Adjustment” on page 48 and “Span Adjustment” on page 48.