PRECONDITION1. All shut down and st

PRECONDITION1. All shut down and start up procedures are updated completely.2. The nitrogen connection for purging U-1400/1500 system has been available, and the line up has finished in site.3. Materials have been prepared, such as hoses, flexes and reducers, etc.4. The new operation of fuel gas system has been updated.5. The plan of production inventory balance has been issued.6. LPG has been stored in T-1954 and T1956 according to the fuel gas inventory plan.7. Steaming out lines has been prepared for C-1490.8. Total 5 furnaces in service, all the columns and inter-drums level in cold section should keep as low as possible and C2/C3 refrigeration compressor suction drums and receivers level and users’ RP/RE level keep as low as possible, keep C2/C3 refrigeration compressor and K1440 running normal and stable.9. Ethylene recovery refrigerant compressor starts up and no ethylene vapor back to C1440 and V1445/V1447 keep low level. 10. According to decon step 19, empty and wash out C1495 ahead of total S/D.11. Ensure hot blow down and cold blow down system is available, V-1911 and V-1910 level should keep as low as possible. Cleaning the filter of P-1911A/B and put in heat system of V-1911 service before plant shut down. The new added temporary hot N2 line to V1910 is available.12. Ensure slop tank of Utility plant can be received large numbers of waste oil and water.13. Methanol injection system (P1577 discharge piping) has been empty and purge before turnaround.