Liquid Cargo Transfer Control: Mud, Fuel and Fresh Water System
Monitor Systems were asked to engineer a control system to fully automate the mud, fuel and fresh water system onboard the Maridive 208 support vessel.
Monitor Systems carried out a survey onboard the Maridive 208 whilst the vessel was in a Nigerian dock.
Engineered Solution: The liquid cargo control system was based around a S7-300 Siemens PLC which was located in the bridge inside an existing cabinet at the request of the vessel crew. The PLC was connected to two remote I/O stations, one for the mud system and a second for the fuel and fresh water system. The system was designed with two HMI control screens.
Mud: New double flange butterfly valves were used, together with new actuators.
Fuel and Fresh Water: The existing valves were kept in the system and new electric actuators were fitted to the existing globe and gate valves.
A remote I/O panel was provided to interface all mud, fuel and fresh water system instrumentation and actuators signals. The fresh water system was designed so that it would share the same I/O panel as the fuel system.
HMI: Two wall mounted 15" HMI's were provided, one for the control room, the second for the bridge. Each screen shows identical system page graphics. The piping overview pages were generated as graphical overviews of the support vessel (mud, fuel, fresh water, fresh water tank level indication, alarm and alarm history, analogue calibration - tank level, valve timing alarm set-up and alarm disable page), with the piping lines drawn in as per drawings and instructions received from the client. The control room and bridge HMI will be used to verify all signals, alarms and sequence testing. All alarm conditions will be submitted to ensure the HMI displays the correct alarm and graphical representation.
