Oil and gas production handbook - Process Control and ...

5.1.4 Fire and Gas Systems
The Fire and Gas System is not generally related to any particular process. Instead it
divides into fire areas by geographical location. Each fire area should be designed to
be self contained, in that it should detect fire and gas by several types of sensors, and
control fire protection and fire fighting devices to contain and fight fire within the
fire area. In case of fire, the area will be partially shut off by closing ventilation fire
dampers. A fire area protection data
sheet typically shows what detection
exists for each fire area and what fire
protection action should be taken in
case of an undesirable event.
A separate package related to fire and
gas is the diesel or electrically driven
fire water pumps for the sprinkler and
deluge ring systems. The type and
number of the detection, protection
and fighting devices depend on the
type of equipment and size of the fire
area and is different for e.g. process
areas, electrical rooms and
accommodations.
Fire detection:
- Gas detection: Combustible and Toxic gas, Electro catalytic or optical
(IR) detector.
- Flame detection: Ultraviolet (UV) or Infra Red (IR) optical detectors
- Fire detection: Heat and Ionic smoke detectors
- Manual pushbuttons
Firefighting, protection:
- Gas based fire-fighting such as CO2
- Foam based fire-fighting
- Water based fire-fighting: Sprinklers, Mist (Water spray) and deluge
- Protection: Interface to emergency shutdown and HVAC fire dampers.
- Warning and escape: PA systems, beacons/lights, fire door and damper
release
For detection, coincidence and voting is often used to false alarms. In such schemes,
it is required that several detectors in the same area detect a fire condition or gas
leakage for automatic reaction. This will include different detection principles e.g. to
trig on fire but not welding or lightening.
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