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COURSEFACILITIES LAYOUT TRAINING
LAYOUT OF FACILITY –SEGREGATION AND ZONING
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LAYOUT OF FACILITY – SEGREGATION AND ZONING
SUBJECTS
• Safety Distance (SD) and Restricted Area Zone (RAZ)
• Air gap
• Fire zones and divisioning (rating of fire divisions)
• Divisioning/segregation by fire/blast walls or by distance
• Ignition sources ISO 13702
• Equipment Categories as per API 14J
• Hazardous Area Classifications
• Level segregation between liquid and gas hydrocarbons
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SEGREGATION AND ZONING
SAFETY DISTANCE & RESTRICTED AREA ZONE• Ref. Maersk Oil, MODES 01
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SEGREGATION AND ZONING
SAFETY DISTANCE & RESTRICTED AREA ZONE• Ref. Maersk Oil, MODES 01
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TOTAL, GS EP SAF 213, Impacted area, restricted area and fire
zones, has similar but a bit different criteria for Impacted Area and
Restricted area
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SEGREGATION AND ZONING
SAFETY DISTANCE & RESTRICTED AREA ZONE
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ThermalRadiation(kW/m²)
Effect
1.2 The sun at noon in summer in northern Europe
2 Minimum to cause pain after 1 minute
< 5 Pain in 15-20 seconds and injury after 30 seconds
> 6 Pain within approx 10 seconds, rapid escape only ispossible
12.5 Significant risk of fatality for medium durationexposure.* Thin steel with insulation on side away from the firemay reach thermal stress level high enough to causestructural failure
25 * Likely fatality for extended exposure and significantrisk of fatality instantly* Spontaneous ignition of wood after long exposure
* Unprotected steel will reach thermal stresstemperature that can cause failure
35 * Cellulosic material will pilot ignite within one minute’sexposure* significant risk of fatality for people exposedinstantaneously
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SEGREGATION AND ZONING
AIR GAP• Certain equipment may be installed in the air gap
• Air gab is defined in the schematic below:
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SEGREGATION AND ZONING
AIR GAP• In more general terms, the air gab is given below
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Other provisions:
•
Tolerances for water depth
• Initial penetration into seabed
• Subsidence, etc.
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SEGREGATION AND ZONING
FIRE ZONES AND DIVISIONING
INTRODUCTION• Main reference is ISO 13702
• Basis for selecting active & passive fire protection is
• Fire and explosion strategy (FES) and fire load analysis
• Evacuation, escape and rescue strategy (EERS) and evacuation
analysis
• Fire loads as part of Dimensioning Accidental Load (DAL as
defined in NORSOK S-001)
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FIRE ZONES AND DIVISIONING
REFERENCES
• IMO SOLAS
• IMO MODU Code
• IMO FTP Code
• MODES 01, Maersk Oil Design Standard, Part 01, Safety Design
• ISO 13702, – Control and mitigation of fires and explosions onoffshore production installations – Requirements and guidelines
• ISO 834-1 – ISO 834-9, Part 1 to 9: Fire resistance tests
• NORSOK S-001, Technical Safety• DNV OS-D301, Fire Protection
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FIRE ZONES AND DIVISIONING
DIVISION INTO FIRE ZONES - PRINCIPLES
• To separate the different fire risk areas from each other
(escalation prevention) – one risk level in one zone
• To ensure a safe escape and evacuation in case of a fire
• Firewater optimization
• Division by distance or by fire wall/deck
• Even a small wellhead platform will require to be divided into at
least 2 fire zones
• First, the wellhead platform will have two different fire risk areas
• secondly a person in one area of the platform will need a second placeto be in case of a fire
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FIRE ZONES AND DIVISIONING
MAIN FIRE ZONING
Requirement for sub-division of a fire zone:
•Size of the zone (m2), among others depending on evacuationrequirements
•Firewater demand for the particular zone.
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FIRE ZONES AND DIVISIONING
MAIN FIRE ZONING - EXAMPLES
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FIRE ZONES AND DIVISIONING
FIRE ZONING – ESDV’S
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• ESDV should be installed where two fire zones interconnect
• The ESDV to be located in the fire zone feeding into the neighbour
zone
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FIRE ZONES AND DIVISIONING
RATING OF DIVISIONS BETWEEN ZONES• The correct selection of fire class depends on two factors:
• Type of fire (cellulosic, hydrocarbon or jet fire)
• Time required with full integrity of the division/wall (depends onescape and evacuation analysis).
• In most cases a time of 60 minutes will be more than sufficient.
• In the first approach, select firewalls for cellulosic fire, i.e. “A”
class divisions.
• Therefore, standard will be A-60 (which in some cases/areas may
be reduced to A-30 or A-15).
• Hydrocarbon fire, heat input > 100 kW/m2 , select H-class
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FIRE ZONES AND DIVISIONING
RATING OF DIVISIONS BETWEEN ZONES• If dimensioning heat input > 150 kW, select J-rating
• For J-rating, a H-60 wall can be conbined with J-15 or J-30 (jet
fire is only relevant for the period of time for blowing down)
• Typically blowdown in 15 minutes
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FIRE ZONES AND DIVISIONING
RATING OF DIVISIONS BETWEEN ZONESTranslation of the ISO 13702, table C.5 nomenclature:
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FIRE ZONES AND DIVISIONING
RATING OF DIVISIONS BETWEEN ZONES
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The table is not symmetrical!
To be read “From” first column areas towards areas in adjacent protected area.
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FIRE ZONES AND DIVISIONING
RATING OF ACCOMODATION DIVISIONS(ref. NORSOK S-001):
• Outer surfaces of LQs shall minimum be A-60
• Heat flux > 100 kW/m2 in a dimensioning fire, minimum class H-60
• No windows in H partitions or walls facing process area
• Fire integrity of bulkheads and decks shall comply with chapter 9of the MODU Code.
• Where MODU Code specifies steel bulkheads internally this shallbe understood as A-0 divisions.
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FIRE ZONES AND DIVISIONING
RATING OF ACCOMODATION DIVISIONS(ref. MODU Code, Table 9):
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FIRE ZONES AND DIVISIONING
SEPARATE ACCOMMODATION PLATFORM• Outer surfaces of LQs shall minimum be A-60
• Barriers as stated in present section should be adhered to
• Rooms containing machinery and flammable fluids such asemergency generators and fire pumps shall be enclosed by
minimum A-60 walls
• The need for H-60 rating of the walls should be evaluated
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FIRE ZONES AND DIVISIONING
EMERGENCY SERVICES(ref. NORSOK S-001, sec. 19.4 ):
• CCR, FW pump systems, emergency power supply with related
distribution equipment and fuel tank shall be protected from the
surroundings by minimum Class A-60 fire divisions.
• Generators (including prime mover), transformers, major
distribution panels, rooms for ventilation equipment and
equipment used for storage of flammable commodities or easily
ignitable material shall be separated from the surroundings of atleast Class A-0 fire divisions.
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FIRE ZONES AND DIVISIONING
FIRE BARRIERS – FIRE/BLAST WALLS OR SEPARATION BY DISTANCE
• Fire barriers may be made by fire rated divisions, i.e. firewalls
with ratings such as A-60, H-60 or similar.
• Division into fire zones may be done both with vertical barriers
(firewalls) and by horizontal barriers (fire rated decks)
• Fire zone division may also be made by distance separation.
• This principle is used when wellheads are located on a separate
platform or if a separate accommodation platform is made.
• Typically this principle requires a bridge of a length of 80 m – 100m.
• Detailed fire load calculations may be used to decide more exactly
on the required bridge length.
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FIRE ZONES AND DIVISIONING
FIRE AND EXPLOSION LOADSFire loads – large pools, large jet fires:
Blast loads:
• Firewalls may need to be rated as blast walls
• Rather open process modules, explosion loads will have amaximum of 0.3 barg.
• This is a value that may be applied in an initial design of modules
and blast walls in modules.
• NORSOK S-001 requires design for 0.7 barg unless more detailed
explosion calculations have been carried out
• The DAL (Design Accidental Loads), must state the loads
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FIRE ZONES AND DIVISIONING
EXAMPLE OF CONCEPTUAL DIVISIONING
Main/Well Intervention DeckA13
A4 A1A8Lower Mezzanine Deck
Roof /Weather Deck
Cellar Deck
WellheadProcess/UtilityAccommodation
27 m
A2A5A9A12
A11
A6A1
0
A14
Flare
A7
Division of platform intofire zones:
A3
H-60/J-15 or J-60
A-60
27 m6 m14 m
Compressors
Plated
Turbines
A16
A15
1 2
Muster area
Life rafts
Sky chute/boardingplatform with life rafts
Utility
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FIRE ZONES AND DIVISIONING
FIREWALL DESIGN• To ensure that flames from one fire zone shall not extend around
the edge of a fire barrier and impinge hydrocarbon containingequipment in the adjacent fire zone, the firewall may need
additional “wings”.• The design may include “wings” to one side, wings to both sides
or extended wings as illustrated in the Figure below.
Firewall
with
"wings"
to
one
side
(horizontal cut through wall)
Firewall
with
"wings"
to
two
sides(horizontal
cut
through
wall)
Extended firewall to ensure that flames from equipment
on
one
side
shall
not
reach
equipment
on
the
other
side
when or if flames from one side of the firewall may go
around
the
edge
of
the
firewall.
extension extension
firewall
firewall
firewall
wing wing
wings
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FIRE ZONES AND DIVISIONING
FIRE INTEGRITY (FIRE CLASS) OF BARRIERS• The traditional and typical fire classes applied for firewalls are:
• Standard fire (cellulosic fire), applicable to A, B and C-ratings
• Hydrocarbon fire applicable to H-ratings when fire load > 100kW/m2.
• The H-rating may be a jet fire rating if this is the design fire case
(fire load > 150 kW/m2).
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FIRE ZONES AND DIVISIONING
THE FIRE TEST CURVES
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IGNITION SOURCES
ISO 13702
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• Chemical reactions
• Oil soaked lagging on hot piping
• Pyrophoric iron sulphide (H2S &
metal corrosion)
• Electrical sparks and arcs
• Electrical motors and generators
•Switches, relays and otherarching components of electricalcircuits
• Electrical wiring mal functioning
•
Electrical welding• Lighting fixtures
• Mechanical sparks
• Lightning
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IGNITION SOURCES
ISO 13702
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• Static electrical sparks
• Fuelling operations
• Filling containers, tanks and
pressure vessels
• High fluid exit velocities (highpressure water sprays, gas jets)
• Drive belt operation
• Shot blasting (velocity)
• Friction
• Flame
• Flaring
• Fired equipment
• Gas welding and cutting
• Hot surfaces
• Fired vessels stacks
•
Engine exhaust
• Heat of compression
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FACILITIES LAYOUT TRAINING COURSE
EQUIPMENT CATEGORIES API 14J
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FACILITIES LAYOUT TRAINING COURSE
EQUIPMENT CATEGORIES API 14J
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AREA CLASSIFICATION
IP 15
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Aim of IP 15• Avoid ignition of those releases that may occur from time to time•
Reduce to an acceptable minimum level the probability of coincidenceof flammable atmosphere and an electrical or other source of ignition• Risk Target is 10-5 year
• IP 15 does not concern major releases (spread of flamables more
than 30 m). These shall be minimised by design and operation to anacceptable residual risk.
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AREA CLASSIFICATION
IP 15
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Zone 0: The part of a hazardous area in which aflammable atmosphere is continuously present or present
for long periods
Zone 1: That part of a hazardous area in which aflammable atmosphere is likely to occur in normaloperation
Zone 2: That part of a hazardous area in which aflammable atmosphere is not likely to occur in normaloperation and, if it occurs, will only exist for a shortperiod.
Non-Hazardous: areas that do not fall into any of theabove. (IS NOT “SAFE AREA”)
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AREA CLASSIFICATION
IP 15 – GRADE OF RELEASE
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Continuous grade release: A release that is continuous or nearly so, orthat occurs frequently and for short periods
Primary grade release: a release that is likely to occur periodically oroccasionally in normal operations, i.e. a release which, in operatingprocedures is anticipated to occur
Secondary grade release: A release that is unlikely to occur innormal operation and, in any event, will do so only infrequently and
for short periods i.e. a release which in operating procedures is notanticipated to occur. Such release may be of unknown size e.g.fracture of a drain or unknown size e.g. corrosion hole.
If it is likely to be present for more than 1000 hours per year.
If it is likely to be present for between 10 to 1000 hours per year.
If it is likely to be present for 1 to 10 hours per year.
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AREA CLASSIFICATION
IP 15
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Continuous grade release Typically Zone 0
Primary grade release Typically Zone 1
Secondary grade release
Typically Zone 2
“Typically” refers that it is ventilation dependent
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AREA CLASSIFICATION
IP 15 - BASIS
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• Natural ventilation and wind without stagnant zones.
•Typically air velocities will not be less than 0.5 m/s and will
frequently be above 2 m/s.
• Where a facility is classified as open area, the hazardous areaclassification of previous slides applies without further ventilation
considerations.
•NB: Risk of reduced natural ventilation – shield/tarpaulins
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AREA CLASSIFICATION
IP 15 – POINT SOURCE METHOD
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AREA CLASSIFICATION
IP 15 – POINT SOURCE METHOD
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Natural Gas
Crude –
Unstabilised
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AREA CLASSIFICATION
IP 15 – POINT SOURCE METHOD – FLUIDCATEGORY
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• Condensate and LPG fall under Category A
• Unstabilized crude falls into Category B
• Stabilized crude oil falls into Category C
• Wet and dry gas fall under Category G(i)
• Produced water fall under Category C
• Injection sea water does not require to be classified
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AREA CLASSIFICATION
IP 15 – POINT SOURCE METHOD
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Piping:
• Fully welded
• Designed according to ANSI/ASME B31.3
Does not require zoning.
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AREA CLASSIFICATION
IP 15 – POINT SOURCE METHOD
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• Flanges:
Secondary grade release source
Broken flanges Primary grade
Ten or more flanges are required within close proximity to createsufficient likelihood of release to justify classification as a secondary
release.
Explains why Fuel gas flange connection to turbines often notclassified
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AREA CLASSIFICATION
IP 15 – POINT SOURCE METHOD
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Valves:
Infrequently used
Well maintained
Frequently used(Control valves)
Secondary grade
Additional Primary grade of 0.3 m
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AREA CLASSIFICATION
IP 15 – POINT SOURCE METHOD
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Pig Receivers
• Pig receivers are opened frequently and are considered as
primary grade release. The hazardous area should be classified as
zone 1.
• When interlock systems are in place, the release when opening
the launcher/receiver will be minor and a hazard radius of 3 m is
suggested in IP 15.
• If the operating procedures include purging or water washing
before opening the launcher/receiver the hazard radii can be
reduced to 1.5 m.
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AREA CLASSIFICATION
IP 15 – POINT SOURCE METHOD
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Pumps
• Secondary grade of release
• Seal leakage rates from standard pumps are generally greaterthan from those pumps fitted with throttle bushes or from high
integrity type pumps.
• A nominal hole size of 2 mm diameter (IP A risk-based approach) canbe taken to represent the leak from a high integrity pump
Note: On multistage pumps, which
normally have a balance line, the seals
will only be subject to a pressurecorresponding to the suction pressure.
The seal pressure for the flushing liquid
is slightly above the pump discharge end
pressure, but this seal pressure will be
lost upon failure of the seal
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AREA CLASSIFICATION
IP 15 – POINT SOURCE METHOD
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AREA CLASSIFICATION
IP 15 – PIG RECEIVERS – ED PLATFORM
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AREA CLASSIFICATION - VENTILATION
VENTILATION (HVAC) - OBJECTIVES• Avoid ingress of gas/vapours into unclassified area (overpressure)
• In enclosures with leak sources, to ensure sufficient ventilation toreach zone 2 classification or unclassified area.
• Provide sufficient air changes to remove fumes, etc.
• Separate HVAC systems in hazardous and non-hazardous areasmust be provided.
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Refer to sec. 7, Safety – Safety
Systems for further about ventilation
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LEVEL SEGREGATION
NORSOK S-001
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Fire and explosion evaluations shall be made along with thedevelopment of the layout to minimize the built in escalation
potential. This shall be ensured through the following principles:
• Equipment and piping containing HP gas should be located in theupper decks above the module support frame or main hull.
• Liquid vessels should be located lower than gas equipment
• Low pressure equipment containing large liquid inventories shouldbe located and arranged so that exposure to jet fires isminimised. (BLEVE)
• Hydrocarbon containing equipment shall be protected from
external impact e.g. dropped objects and missiles.
• Confined and congested modules shall be avoided.
• Long narrow modules shall be avoided.
S G G O
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LEVEL SEGREGATION
GUIDE – LEVEL SEGREGATION
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THANK YOU
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THANK YOU
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