Field Mounting And Complete Calibration Reciprocating Valves Using 87/88; Air To Open / Direct Acting Positioner; Air To Open / Reverse Acting Positioner (4700P/4800P Only) - GE Masoneilan 4700P Maintenance Manual

Field Mounting and Complete Calibration
Reciprocating Valves using 87/88 Actuators
Define valve action and positioner action. (4700E/4800E is direct action only) If lever S/A (3) is not
on proper side (Left or Right) as determined from data from "Cam Lobe Selection and Lever Arm
Orientation" on page 65, change to correct position. Refer to "Changing Lever S/A Orientation"
on page 45. If positioner is not on valve refer to Figure 5 on page 23 through Figure 10 on
page 30 for mounting and linkage connection procedures. If positioner is reverse acting (4700P/
4800P only) do not assemble cam to shaft at this time. Make pneumatic connections per
Figure 11 on page 33 for action desired (4700P/4800P), or electrical and pneumatic connections
for 4700E/4800E (direct action only). Proceed to proper section below.

Air to Open / Direct Acting Positioner

See Figure 19 on page 68 and Figure 20 on page 71.
1. Apply lower value of instrument signal. (i.e. 3 psi if 3-15 psi 4700P/4800P or 4 mA if
4-20 mA 4700E/4800E).
2. Unlock zero locknut (4C) and turnbuckle locknut (107). Adjust zero by turning both
the zero nut (4B) and turnbuckle (106) until the low signal line of the cam is aligned
with the positioner case raised reference line and the travel indicator shows
closed position. Retighten both locknuts.
3. Apply full scale value of instrument signal (i.e. 15 psi or 20 mA.) and note position
of travel indicator. If travel is not correct, perform span adjustment. Refer to
"Span Adjustment" on page 48.
4. Repeat zero and span adjustments per "Zero Adjustment" on page 48 and "Span
Adjustment" on page 48 until travel range is correct. After adjustments are
satisfactory, re-tighten the spring locking screw (8), zero locknut (4C), and
turnbuckle locknut (107).

Air to Open / Reverse Acting Positioner (4700P/4800P only)

Figure 19 on page 68.
1. Disconnect air line from positioner to actuator at actuator. Run an independent
regulated air line to the actuator. Slowly apply proper air pressure through the
regulator to open the valve. (Handwheel may be used to open valve instead of
regulated air line.) Align the travel indicator with the open end of travel scale. Do
not overtravel.
2. Place cam (26) on to cam shaft with selected cam lobe facing forward and low
signal line approximately aligned with positioner case raised reference line.
Secure cam to shaft using washer (27) and screw (28).
3. Slowly reduce pressure applied to actuator to zero (If handwheel was used, back if
off fully). Cam will now be at high signal line.
4. Disconnect the independent regulated air line and connect the positioner output
line to the actuator. Connect supply pressure and signal to the positioner.
54 | =GE Oil & Gas
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