GE Masoneilan 4700E, Maintenance Manual

Page: 59 / 80

Masoneilan 4700P/E & 4800P/E Positioners Manual =
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Body
Shut off the air supply. Disconnect air lines, linkage if reciprocating, and electrical connections if
4700E/4800E. If positioner is reverse acting, refer to applicable section under “Cam Lobe
Change” on page 49 to safely remove cam. Remove screw (28), washer (27), cam (26). Separate
positioner from actuator by removing screws (29) and washers (30).
Disassembly
See Figure 19 on page 68 or Figure 20 on page 71.
1. Remove pressure gauges (12) (13), and on 4700P/4800P only (14).
2. Remove the pilot subassembly (11).
3. Remove retaining ring (17), washer (16), lever S/A (3), and spring (5).
4. On 4700E/4800E only, remove 4 screws (21) to separate I/P module from body.
CAUTION
Do not damage or lose the three O-rings on bottom of module.
5. Remove cap screws (10) and separate body S/A from the case S/A.
6. Remove the diaphragm assembly (9), and reducer plate if 6-30 psi range 4700P/
4800P.
7. Clean the body (1). Avoid the use of detergents that might deteriorate the
diaphragm S/A. Use isopropyl alcohol. Do not use chloride-based solvents.
8. On 4700E/4800E, carefully remove the three O-rings from the bottom of the
module. Inspect for any nicks or deterioration. Replace if necessary. Clean bottom
of module using isopropyl alcohol. Carefully reassemble O-rings into grooves.
Make sure they are seated in bottom of groove.
CAUTION
Do not use any lubrication on O-rings or base.