When replacing the displacement sensor DET100A (LVDT) online, it is necessary to ensure system stability and avoid major disturbances. The following are detailed online replacement steps and precautions:

Online replacement steps

1. Preparation work:

-Ensure there are sufficient spare parts and tools available for replacement and adjustment when needed.

-Prepare a work order or operation guide, listing the replacement steps and precautions to be taken.

2. Close the valve:

-Before replacing LVDT, it is usually necessary to close the valve and ensure that it stops running. This can be achieved through a control system or manual operation.

3. Mark the location of the faulty LVDT:

-Before replacement, mark the location of the faulty LVDT. This helps ensure that the installation position of the new sensor is consistent with the original position.

4. Disassemble the faulty LVDT:

-Follow the relevant operating instructions to disassemble the faulty LVDT. Pay attention to protecting the site and follow safety operating procedures.

5. Install a new LVDT:

-Install a new LVDT and ensure that the installation position is as consistent as possible with the marked position. Tighten the screws and connect the wires.

6. Valve position adjustment:

-Gradually adjust the valve from the closed state to the target position as needed. This can be done through a control system to ensure stable operation of the valve at different positions.

7. Feedback signal testing:

-Monitor the feedback signal of the new LVDT through the control system at different positions of the valve. Confirm that the change in signal is consistent with the change in valve position.

8. Valve action test:

-By controlling the system or manually operating, gradually move the valve from closed to open, and then close it again. Observe whether the valve operates smoothly and as expected.

9. Calibration and adjustment:

-If necessary, calibrate and adjust the newly installed LVDT to ensure that its output signal is consistent with the actual valve position.

10. Restore normal operation:

-If all experiments and adjustments are successful, the valve can be restored to its normal operating state. Ensure the stable operation of the system and monitor the working condition of the sensors.

11. Records and Reports:

-Record key data and observation results during the experimental process. If there are any abnormal situations or further analysis is needed, report to the corresponding maintenance team.

precautions

1. Maintain system stability:

-During the replacement process, it is necessary to maintain system stability and avoid significant disturbances. The tripping and shutdown caused by LVDT malfunction is unforgivable.

2. Monitoring by the operation supervisor and thermal supervisor:

-The replacement process operation supervisor and thermal supervisor must be present for process monitoring to ensure that the entire process is controllable and under control.

3. Gradually adjust the valve:

-After replacement, gradually adjust the valve command from 0% to 100%, and then from 100% to 0%, compare the consistency between the valve command and feedback, and adjust the linearity of the valve.

4. Ensure that the actual position of the valve is stable:

-During the entire replacement process, the actual position of the valve should be kept stable to avoid significant swinging due to improper operation.