Fisher 3 that the travel pin remains perpendicular to connector arm during this process
2. tighten the cap nut and re-check the the arm at mid-travel position, if the zero degree marks don't align, repeat the procedure.
(b) For special travel pin setting (when travel pin setting greater than total actuator travel):-
The arm will not rotate 30 degrees in one direction as the valve is stroked and therefore the 30 degree marks will fall short of aligning with case index marks. only
thing, the 'gap' between the index marks on the case and rotary shaft arm should be same in both directions (i.e., while stroking to 0 and 100%). If gap is not the
same, adjust the pin position as described above to make it same.
3. WORKING
Working is as explained in the video and pg 32 in the datasheet. The valve positioner can be used in direct and reverse options.
4. BEAM ALIGNMENT
The beam is leveled at the factory prior to shipment. Once the beam is leveled, no additional leveling should be required unless the
beam pivot pin or the bellows assembly pivot pin are changed, the bellows assembly or range spring (to increase the range from 3-15 psi to 6-30 psi) are replaced, or
the valve positioner is changed to split range operation.
Names of important components to understand the Alignment:-
see fig-15
Rotary shaft arm (), nozzle lock nut (), nozzle (), flapper assembly (), follower assembly locknut(),follower assembly (),bellows assembly locknut(),bellows pivot pin
(),beam pivot pin locknut(), beam pivot pin().
procedure for beam alignment given in pg 29 in datasheet.
5. CALIBRATION
procedure for calibration given in pg 31 in datasheet, the procedure in brief is given below:- see the actual pic:- positioner-photo
1. Keep the flapper assy at position 6 on the scale and stroke to 50 % of stem travel. if the stem does not match the 50% range, adjust the nozzle and tighten the
nozzle lock nut.
2. When valve is stroked to zero and if the actuator does not move to the proper end of travel, loosen the nozzle lock nut and adjust the nozzle for zero.
3. When valve is stroked to 100% and if actuator does not move to proper end of travel, adjust the flapper assembly to higher value on the scale to reach 100% or if
the actuator is already reaching 100% at a lower signal value (say 90% input),then adjust flapper assy to lower value on the scale.
4. If span is adjusted, then re-check for zero adjustment
5. The positioner will fully vent or pressurize the actuator to supply pressure at the ends of actuator travel when the positioner is
calibrated correctly. Failure to properly calibrate the positioner may result in reduced seat loading
6. MAINTENANCE
6.1 Changing the range spring (pg 36 in datasheet) see FIG-21
The device can operate for supply pressure 3-15 psi and 6-30 psi. The higer range operation (6-30 psi) can be done by changing the range spring.(pg 36 in datasheet)
6.2 Adjusting the flapper pivot (pg 38 in datasheet) fig-20
If the flapper is touching the support or if need is felt to adjust the flapper, all you have to do is to loosen the two nuts (19C) which are marked by paint, push the
ear (19K) slightly such that the flapper does not touch the support and tighten the two nuts (19C). For more details, follow instruction in page 38 in datasheet
6.3 Replacing the nozzle O ring (pg 38 in datasheet)