In my plant, Vaccum Column LT LP tapping body nozzle is badly choked, all the dechoking options tried but no success found. We have only one LT tappings. As of now we have installed a PI at bottom in place of LT HP tapping, on the basis of this PI value level column is being operated. However this is not the permanent solution unless until we shutdown the column. Is there any other option available to monitor level of column??