ICSS Modification for Plant wide Maintenance Override Switch philosophy implementation and Single point of failure to avoid plant trip

GAS has successfully executed an EPIC contract for the modification of an Integrated Control and Safety System for a GTL plant in Ras Laffan Industrial city.

GAS’s scope under the EPIC contract included:

DCS Modifications such as High and Low alarms, deviation alarms between DCS and SIS transmitter, transmitter re-range and clamping the range to avoid I/O bad.

SIS modifications to change the voting logic from existing 1oo1 mode to required mode(2oo2 or 2oo3) as applicable.

Modifications to introduce redundancy of transmitters so that the availability and reliability of the trip transmitters are improved.

Shall prepare the required deliverables to execute the proposed modifications.

Shall arrange and facilitate detail design review meetings where all design specifications are reviewed and accepted.

Shall generate detailed software configuration specifications for MOS philosophy modifications for IA Foxboro DCS and SIS Triconex controllers. The detailed software configuration specification utilize the strengths and built in functionality of the SIS and DCS such that the software configuration is simple and maintainable.

Shall redline affected Instrument logic diagram, loop diagram, auxiliary console drawings and nest loading with required changes.

Shall conduct site survey and identify new Foxdraw HMI screen to be designed.

Shall update the operating procedures especially for MOS overrides and affected PT compensated flows.

Offline implementation using test setup for simulation and testing.

Shall facilitate FAT and SAT with appropriate functional test procedures.

Technology: IA Foxboro DCS and Triconex SIS

Sector : Oil and Gas