Quench water: replace the manual quench system for 0906 with a control valve, flow meter (-2" line) and new quills. Installed a butterfly valve (similar low-pressure restriction) prior to the steam entering the unit to enable a more complete bypass. Higher temperatures to the unit would be addressed by the quench identified above.
The upper 12 rows in the convection section were changed resulting in adjustments on heat recovery in the process stream to the radiant section, increased the heat recovery in the HP steam coil, and reduced heat recovery in the process gas flow to the cobalt molybdenum drum. The project needs to ensure that operations have sufficient controls to address start-up, shut down, and normal operating upsets.