1 Process Isolation 0.25 h/conn. Time needed to close a SBB and to check proper isolation expert judgment 2 Process Isolation 0.50 h/conn. Time needed to close a DBB and to check proper isolation expert judgment 3 Depressurization 0.50 h Time needed to reach atmospheric pressure by opening BDV and discharging to flare expert judgment 4 Cool down See dedicated table expert judgment 5 Electrical Isolation 0.25 h Time needed to locate and disconnect the circuit breaker and to verify isolation in field according to HSE procedures expert judgment 6 Draining 0.50 h Time needed to open connections to drain system (or to connect temporary lines) expert judgment 7 Draining 2.50 m/s Liquid velocity in the draining line expert judgment 8 Purging 0.50 h Time needed to connect the nitrogen generator expert judgment 9 Purging 2.00 bar Pressurization pressure (applicable to purging by pressurization/depr. cycles) expert judgment 10 Purging 1.00 bar Discharge pressure (applicable to purging by pressurization/depr. cycles) expert judgment 11 Purging 1,400.00 Sm3/h Nitrogen generator flow rate TO BE DEFINED BASED ON PROJECT PROJECT SOURCE 12 Purging 3.00 n/a Sweeping factor expert judgment 13 Blinding 0.50 h/conn. Time needed to apply/remove positive isolation devices (i.e. spectacles, blind flanges, spools) expert judgment 14 Ventilation 0.50 h Time needed to open a manway expert judgment 15 Ventilation 1.00 min/m3 Time needed for ventilation expert judgment 16 Ventilation 24.00 h Maximum ventilation time expert judgment 17 Washing See dedicated table ENI Std. 20560_430_rev02 18 Item Removal See dedicated table expert judgment 19 Reinstalling 0.50 h/conn. Time needed to remove positive isolation devices or to reinstall spools expert judgment 20 Reinstalling 0.25 h/conn. Time needed to open isolation valves expert judgment 21 Reinstalling Time needed to restore other mechanical connections: see dedicated table expert judgment 22 Leak test 0.50 h Time needed to connect the high pressure nitrogen generator expert judgment 23 Leak test 1.10 Leak test pressure to operating pressure ratio expert judgment 24 Leak test 1,400.00 Sm3/h High pressure nitrogen flow rate TO BE DEFINED BASED ON PROJECT PROJECT SOURCE 25 Leak test 0.25 h/conn. Time needed to check each flange for leaks after the test pressure is achieved expert judgment 26 Air Removal 0.50 h Time needed to connect the nitrogen generator expert judgment 27 Air Removal 0.21 Initial oxygen concentration (in case leak test has not been performed) expert judgment 28 Air Removal 0.03 Target oxygen concentration expert judgment 29 Air Removal 2.00 Pressurization pressure (applicable to purging by pressurization/depr. cycles) Assumed equal to Purging expert judgment 30 Air Removal 1.00 Discharge pressure (applicable to purging by pressurization/depr. cycles) Assumed equal to Purging expert judgment 31 Air Removal 1,400.00 Nitrogen generator flow rate Assumed equal to Purging expert judgment 342101BPST02508 34210ABPRV02054 32 Commissioning & Start up 1.00 h Temperature restoring time expert judgment 33 Commissioning & Start up 0.50 h Pressure restoring time Assumed equal to Depressurization time expert judgment 34 Commissioning & Start up Level restoring time Assumed equal to Draining time expert judgment 35 2.00 Maximum numbers of crews working in parallel for isolation/blinding expert judgment 36 0.80 Efficiency of maintenance crew Not applied to essentially labor-free activities (i.e. Cool down and Ventilation) expert judgment 37 Item conveyance to workshop 1.00 h Loading / Unloading expert judgment 38 Item conveyance to workshop 1.00 h Travel to WS expert judgment