GE Masoneilan 4700E, Maintenance Manual

Page: 47 / 80

Before commencing any calibration or maintenance procedure on
these positioners, ensure that the valves under control are iso-
lated from the controlled process and that the area is verified as
nonhazardous.
Masoneilan 4700P/E & 4800P/E Positioners Manual =
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General
The Model 4700P/4700E and 4800P/4800E positioner, when factory mounted, has been calibrat-
ed for the proper valve, valve action, and positioner action. If, for any reason, the cam holder (36)
setting has been disturbed (i.e., a change of positioner action, field mounting, maintenance, etc.),
it is necessary to follow all steps of the calibration instructions, according to desired actuator ac-
tion and positioner action.
For proper performance when the valve is installed, calibrate the positioner as part of the normal
installation procedure. Shipping, handling and installation can cause some changes in the
calibration.
Calibration may entail just a simple adjustment or a complete field mount. Define the scope of
work and follow the applicable sections.
Do not attempt to remove cam if cam is not at low signal line of
lobe (low end of range). Refer to calibration instruction for proper
valve action and positioner action before removing or replacing
cam and tightening set screws (35) to proper torque.
WARNING
CAUTION
Calibration