Fire & Gas Detection & Protection Systems (FGS)

The Fire and Gas Detection system provides early and reliable detection of the fire or gas, continuously monitor all areas where a fire or an accumulation of a flammable or explosive gas mixture may occur.  On detection of any of these events the Fire and Gas Detection system shall alert personnel and initiate timely executive action to minimize the consequences.

It is an element of the unit Integrated Control and Safety System (ICSS) and is defined as emergency electrical equipment, and as such its reliability and availability must be ensured.  In order to achieve this assurance the necessary levels of equipment redundancy and system self-test shall be incorporated and a high level of QA / QC shall be carried out on all phases of the FGS design / construction / installation and commissioning.

Generally, techniques of redundancy and replication shall be used to avoid common mode failure points such that one fault in the system does not make the system inoperable.  This applies to both the Control System and field devices.  SIL analysis methods, as described in IEC 61508/61511 shall in general not be used for the design of the FGS, as risk has already been reduced to ALARP level by the ESD system.

The FGS continuously monitors heat, infrared flame, smoke, temperature, manual alarm call-points and toxic or combustible gas levels with the use of dedicated field devices.  The status of all FGS detectors shall be presented on HMI and the Fire and Gas Matrix panel. If any combination of them (within a zone) exceeds a pre-determined level, the system will raise the alarm and take automatic action.

Typical actions from a FGS is to alert personnel, release fire-fighting systems, emergency ventilation control, stop flow of minor hydrocarbon sources such as diesel distribution to consumers, isolate local electrical equipment, initiating ESD and PSD actions, isolate electrical equipment and to close watertight doors and fire doors.  Audible and visual alarms for Fire or Gas shall be initiated throughout the unit upon detection of gas or fire.

It shall depend upon the priority of alarm status, initiate the automatic operation of the following functions:

  • Unit Status alarms (Fire or Gas)
  • Emergency Shutdowns via the FGS / SIS system.

To conclude, for today’s manufacturers the safety of their facilities, personnel, production and the environment is crucial to achieving on-time delivery and minimizing any potential losses.  Therefore to meet their safety needs while ensuring operational and business readiness at project start-up is a must.