The Wu-ku tank farm is of crucial importance for supplying the metropolitan area of the Taiwanese capital Taipeh with petroleum products. The tanks are filled via pipelines from Keelung harbour. The further distribution is made from the tank farm. For example, one pipeline directly carries kerosene to the airport. Demands on the operational reliability are therefore extremely high.
A central milestone in modernising the tank farm was to automate the hitherto manually operated valves using electronic actuators. The plant operator, the Chinese Petroleum Corporation, was searching for an actuator manufacturing who would, on the one hand, ensure the integration of the new actuators into the existing control system and, on the other hand, allow for smooth and fast transition to the new technology while minimising any plant downtimes. Moreover, the communication channels had to be designed as redundant version. Altogether, 32 actuators had to be replaced.
The integral solution including the SIMA Master Station, as proposed by AUMA, proved ideal. The explosion-proof AUMA actuators were connected to the SIMA Station via a Modbus RTU loop. If the loop is interrupted in one spot, the SIMA diverts the communication and treats the disrupted loop as two line structures. This way, the communication to all actuators is maintained. The SIMA allows for fast setting of the actuator communication parameters and communication testing; thus, the commissioning was rapidly performed.
Fig. 1: The actuators are connected to the SIMA via a Modbus RTU loop