Process control system is PLC based system which interfaces with various other sub systems. It can be called as heart of TAS. The main functions of process control system are
The process control system is PLC based system with PC based operator stations. It mainly control and monitor the following areas / equipment
a) Pumping plant: The complete automatic start and stop of pumps based on the process requirements are controlled by process control PLC system
b) Motorized valves: Motorized valves are either hardwired or multidropped using communication bus and connected to process control PLC. All the motorized valves are operated and monitored by process control PLC as per process requirement. As per OISD guidelines motor operated valve (MOV) on inlet, outlet and recirculation lines should be located outside the dyke.
c) Double Block and Bleed Valves: The purpose of DBBV is to have positive isolation of lines / tanks. Remote operation and monitoring of DBBV is carried out through process control PLC.
d) Dyke valve position monitoring: As per OISD guidelines Dyke drain Valves shall be provided with position indication and alarm system in the event of opening the valve.
e) Truck Queue Management System: The trucks arriving at terminals shall register at the entry gate. After registration vehicle is parked in parking area and driver goes and rest in driver rest room. A LED monitor is located in Driver rest room provided in parking area. According to the process requirement and first cum first basis the vehicle number will be displayed on the monitor for driver to report at the entry gate. This system will be part of process control system PLC.
f) The process control system PLC shall be Interfaced with the following systems for efficient operation of the terminal.
– Tank Farm Management System
– Truck Lorry Filling System
– Weighbridge
– RFID Based Truck Identification System
– Traffic Signaling
– RIM seal protection
– Upstream and Downstream control system