Positioner calibration model 3582
Fisher Model 3582 Calibration of Fisher Company is one of the most popular and widely used pneumatic positioners that has been used in factories related to Iran’s oil and petrochemical industries. Here’s how to align the blade and calibrate Fisher’s 3582 positioner.
The method mentioned in this article can also be used to calibrate Model 3582i positioners and Model 3583 stem position transmitters. Note that if the positioner is already in service and is sure to adjust its mechanical parts, you can skip the beam alignment and perform the calibration operation completely. However, if the positioner is newly installed on the valve control, you must follow the steps of aligning the beam and make sure that the mechanical components of the positioner are in the correct position.
The purpose of aligning the beam is:
- Ensure the correct position of the mechanical components of the positioner
- Provide a suitable pressure source
- Provides an input signal to the positioner. It can be manually adjusted to the midpoint of a desired input signal range.
In fact, by aligning the beam, we prepare the positioner to be calibrated.
Follow the steps below to align the Beam:
- Using a wheelbarrow or a hand loader, stroke the actuator to 50%. Raise the rotary shaft arm so that the zero-degree mark on the Rotary shaft arm aligns with the body mark. Then place the Travel pin in place so that it is perpendicular to the arm and in line with the mark of the overall movement of our actuator.
If the movement of our stem is less than 29mm, the Travel pin should be set to the 1-1.8 inches movement indicator.
- Loosen the nut on the back of the nozzle and turn the nozzle clockwise to reach its lowest point. Then turn the nozzle 4 times counterclockwise and tighten the locknut.
For proper operation, the flopper must face the nozzle. Check the flap / nozzle arrangement and make sure the flap is not loose, not bent or twisted.
- Remove any air pressure applied to the actuator and also release it to move the wheelbarrow. Connect the positioner output tip to the actuator.
- Connect the positioner input and place the input signal in the middle of the range. For example, for a 3582 positioner with an input signal range of 0.2-1.0 bar, set the input signal to 0.6 bar. Then apply air supply to the positioner.
- Move the flapper assembly and set the Beam to zero on the rating. The zero-degree mark on the rotating shaft arm must be flush with the body mark. If not, loosen the nut on the back of the follower assembly screw and adjust the follower assembly screw until the zero mark on the Rotary shaft arm aligns with the body mark. Tighten the back nut of the follower smilie strap.
- Place the flapper assembly on position 10 in the direction of direct Beam rating operation. Loosen the zero-degree mark on the rotating shaft of the jumper shaft and adjust the spindle pin. Until the zero degree mark on the shaft rotating arm is aligned with the body mark. Tighten the back nut of the belose assembly strap.
- Move the flapper assembly to the left and set it to position 10, which is on the reverse side of the beam calibration function. If not, loosen the back nut of the Beam shaft pin and adjust the Beam shaft pin so that the zero-degree mark on the rotating shaft arm is flush with the body mark. Tighten the back nut of the Beam shaft pin.
- Repeat steps 5, 6 and 7 to optimize alignment. Check again that the flapper is positioned exactly on the nozzle. If not, adjust the nozzle and re-align the beam. After aligning the positioner, the valve is ready for calibration.
Fisher Model 3582 Position Calibration:
Follow the steps below to calibrate Fisher’s 3582 Positioner:
- Disconnect the positioner air supply. Connect the output of the positioner to the actuator with a tube. Connect the positioner input and set the input signal to the middle of the range. For example, if our input range is 3-15 psig, we set the input signal to 9 psi.
- Move the flapper assembly and place it almost on position 6. So if we want the control function to be Direct, place the flopper assembly on the right quadrant of the circle and on position 6, and if we want the control function to be Reverse, place the flapper assembly on the left quadrant and on position 6. Now apply Supply pressure to the positioner. The zero-degree mark on the rotating shaft arm must be flush with the body mark, and the actuator must be within the 50% position. If this does not happen, make sure the Linkage or Cam is not installed properly. The nozzle height may need to be slightly adjusted to match the input signal value.
- Apply a signal with a command equal to the value of the lower range of the input signal range to the input of the positioner. Unscrew the nut on the back of the nozzle and adjust the nozzle so that the actuator moves and is at the end point of its movement. In fact, by adjusting the position of the nozzle, the Zero trim adjustment operation can be performed. Note that the reference zero point will also change whenever you change the nozzle position.
- A command signal is equal to the high value range. Apply the input signal to the positioner input and observe the movement of the valve stem. If the movement of the stem is shorter than the desired range, moving the flapper assembly to a higher number on the beam can reduce the range of motion.
- Repeat steps 3 and 4 until the actuator moves correctly. Repeat step 3 each time you change the position of the flapper assembly to achieve the proper Zero.
Moving the flapper assembly to 0 on the Beam reduces the movement of the stem. The minimum movement of the existing stem to adjust the movement pins is different. For example, to set the motion pin to 2 by applying a high value of the input signal range, the minimum possible stem movement will be 11mm.
Note that if the valve control is installed on the line and is in service, in order to be able to test and calibrate it, the operator must first set the controller to manual mode and isolate the valve control from the process.
Change the position of the valve position:
No additional components are required to convert the position of a 3582 positioner from direct operation to reverse operation or vice versa. Rather, it is the position of the flapper assembly on the beam that determines the positioner’s performance. The beam is divided into two quadrants. A quarter circle of Beam whose position the direct function is labeled with is DIRECT and a quarter circle of Beam whose position is reversed is labeled REVERSE. To change the position of the positioner, simply move the flapper assembly on the beam and place it on the quadrilateral of the opposite circle. Now we can start the calibration steps and use the positioner according to the desired function.
How the Fisher 3582 Positioner Works:
The input signal received from the pneumatic controller or I / P transducer is connected to the bellows.
When the input signal increases, the bellows expands and moves the beam. The Beam axis moves the flopper around the nozzle axis towards the nozzle and approaches it. The nozzle pressure increases and due to the operation of the relay, the output pressure of the positioner that is applied to the actuator increases. Increasing the pressure applied to the actuator causes the actuator stem to move downwards. The movement of the stem is given to the Beam by a cam. By rotating the cam, move the beam axis around the feedback axis of the flapper and move it slightly away from the nozzle. The nozzle pressure decreases and as a result the output pressure of the positioner applied to the actuator decreases. The movement of the stem continues and again the flapper moves a little further away from the nozzle and this process continues until the positioner reaches equilibrium.
As the input signal decreases the input signal shrinks and the Beam axis moves around the input axis of the flapper and moves away from the nozzle. The nozzle pressure is reduced and the relay allows the diaphragm chamber pressure to be released into the atmosphere. The actuator stem moves upwards. The stem movement is fed to the beam by the cam and the flapper moves closer to the nozzle. When the positioner reaches equilibrium, the movement of the stem continues and again the flapper moves slightly away from the nozzle, and this process continues until the positioner reaches equilibrium.
When the input signal decreases, the shutter shrinks and moves the beam axis around the flap input axis line away from the nozzle. The nozzle pressure decreases and the relay allows the diaphragm chamber pressure to be released into the atmosphere. Moves upwards The movement of the stem is fed to the beam by the cam and the flapper approaches the nozzle. When the positioner reaches equilibrium, the movement of the stem stops and the flapper is positioned to prevent any further reduction of the diaphragm chamber pressure. The principle of operation of a reverse position positioner is similar to that of a direct position positioner, except that the aperture pressure decreases as the input signal increases. Conversely, a decrease in the input signal causes an increase in the pressure applied to the diaphragm chamber.
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