The following requirements shall be shown:
• changes of shell diameter (if any);
• top and bottom trays, and those trays that are necessary to locate feed, reflux, and product lines;
• all draw-off trays with tray number and diagrammatic representation of the downcomer position (e.g. side or center);
• all nozzles, manholes, instrument connections, drains, vents, pump-out and steam-out connections, blank-off ventilations, vortex breakers, safety/relief valve connections, sample connections, and handholds;
• skirt or legs, top and bottom tangent lines;
• elevations above base line to bottom tangent line of column or to bottom of horizontal drum;
• the position of high high liquid level (HHLL), ...