Catalyst Loading / Unloading
All reactor piping shall be clear of the access areas of loading / unloading of catalyst. Reactor with top man way nozzle for catalyst charging is provided with a flanged elbow Nozzle on this man way to connect outlet piping. This flanged elbow nozzle is to facilitate spool removal during catalyst charging.
The catalyst unloading / dump nozzle elevation of reactor bottom is to be decided based on the provision of a catalyst shaker / vibrator equipment to be bolted onto this unloading nozzle.
Platforms provided around reactors and for access to piping and valves shall generally be supported from separate structure.
However the platform can be connected to vessel shell if welding is allowed and cleats are provided.
Generally reactor shell clips / cleats are to be avoided.
Piping connected to reactor top outlet nozzle needs to be additionally supported from structure. (This support acts temporarily) since this connection to man way is dismantled during catalyst charging.
Swing elbows type arrangement is preferred on the regeneration piping from reactor bottom as against valves and bypasses. This eliminates stress problems to some extent since the used hot line and unused cold line are not permanently interconnected.
All valves provided on reactor hydrogen service lines be it inline, vent, drain and instrument valves shall always be double blocked type. Also snuffing steam rings shall be provided around hydrogen service flanges size over 12″.
Ring Joint Flanges
For reactor process piping where spec. calls for ring joint flanges the piping shall be arranged so as to allow for valve removal.