1. Before adjusting the gain, place controller on manual and isolate the valve from the process.
2. Turn off supply air to control valve actuator.
3. Using a 5/64-inch allen wrench,
loosen both upper and lower lock screws
about one half turn. Do not loosen the
spacer nut. (See Figure 6.)
4. By grasping adjust lever, carefully rotate gain adjust assembly to desired position.
make sure both upper and lower gain adjust plates rotate together. When they are rotated to the new position, the
connecting spring should be perpendicular to the plates.
Caution: To avoid damaging gain adjust connecting sping mechanism, make sure both upper and lower gain
adjust plates rotate together. When they are rotated to the new position, the connecting sping shold be
perpendicular to the plates.
5. When the gain is set to the desired position, firmly tighten both lock screws.
6. Turn on the supply pressure. Check actuator responsiveness by providing a step signal to positioner. When gain is set
as desired, check valve zero and span calibration and re-calibrate if needed.
7. Return the valve to service.
Calibrating I/P Module Zero and Span Settings
:
NOTE: Although calibration can be accomplished using the output pressure gauge on the I/P module, its accuracy is ±3
percent. The standard gauge should be removed only for calibration and more accurate calibration equipment of ±0.1
percent of span should be used. The pressure gauge port is 1/8-inch NPT. Calibration manifolds are available from the
factory (Part No. 97370).
1. Connect I/P module to a supply pressure between 30 to 150 psi.
2. Remove I/P module housing cover. (See Figure 7.)
WARNING: Be certain power to I/P module is disconnected before removing housing cover in explosive
atmospheres; otherwise personal injury may occur.
3. Before adjusting the zero and span, be certain the MPC feature is disabled. Refer to Step 7 in the ‘Adjusting the
Minimum Pressure Cutoff Feature’ section
4.
Connect a current source to the terminal block on circuit board
.
