In Unipol fluidized bed gas phase polymerization process of polypropylene (PP) impact co-polymer (ICP) production, PP resin is transferred from reactor-1 to reactor-2 via IRTS (Inter resin transfer system). Due to fouling in IRTS (transfer tank and transfer tank filter) and some times due to actuation of faulty level switch (high level), ICP production has to be stopped. What may be probable reasons of IRTS frequent fouling? The level switch is of neucleonic type. What may be the reasons of actuation of faulty level switch? How to improve operational reliability of Impact co-polymer production?