Piping Group & Equipment Space

8/3/2019 Piping Group & Equipment Space

1/41

PREPARED

BY PTT PUBLIC COMPANY LIMITEDCHECKED

BY ONSHORE COMPRESSOR STATION 4

PROJECT

APPROVED

BY

CERTIFIED

(PTT)

REV.

NO.

DATE REVISED

BY

APPROVED

BY

DESCRIPTION

D118-Feb-

08ISSUED FOR ITB

D2 1-Jul-08 REVISION ISSUED FOR ITB

SPECIFICATION FOR

PIPING GROUP EQUIPMENT SPACING

SPC-0804.02-50.03 REV.D2

TOTAL 41 PAGES

AREA CODE OF SITE LOCATION

GENERAL AREA: 010

.

PTT PLC. CONTRACT NO. PTT PLC. PROJECT NO.

0804.02


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PTT PUBLIC COMPANY LIMITED

ENGINEERING SPECIFICATION

SPC-0804.02-50.03

PAGE: 2 OF 41

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CONTENT

SECTION

1.0 SCOPE ..................................................................................................... 3

2.0 GENERAL CONSIDERATIONS ...................................................................... 3

3.0 DEFINITIONS ............................................................................................ 4

4.0 STANDARDS AND GUIDES......................................................................... 5

5.0 SPACING OF UNITS AND AREAS ................................................................ 6

6.0 ON SITE SPACING....................................................................................12

7.0 OFFSITE SPACING....................................................................................22

8.0 TANKAGE................................................................................................27


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1.0 SCOPE

The scope of this standard is to define the basic design, equipment spacingcriteria and standards to be used in the layout of plant and equipment.

The recommendations are based on current practice within the industry and are

intended, as a minimum, to satisfy the requirements of all relevant Government

safety recommendations.

Where applicable this standard is to be read and utilised in conjunction with

relevant National mandatory standards, listed codes and regulations which also

apply to the location of the project.

In the event of any conflict, Contractor shall seek clarification from the Clientbefore proceeding. Generally, the most stringent requirements shall apply.

This standard is not applicable for the following: -

Toxic Materials Handling Plant

Explosives Plant

Nuclear Plant

Pharmaceutical Plant

Equipment within Enclosed Buildings

Offshore Facilities

Well Drilling Sites for Oil or Gas

2.0 GENERAL CONSIDERATIONS

The objective of the spacing recommendations is to ensure that maximum

economical use is made of available plot areas, compatible with the safety ofpersonnel and vulnerability of plant.

In achieving this end, consideration shall be given to:

a) Accessibility for normal operation and maintenance

b) Accessibility for fire fighting

c) Accessibility for emergency shutdown

d) Accessibility for evacuation of personnel

e) Segregation of high-risk facilities and sources of ignition

f) Protection of critical emergency facilities

g) Protection of adjacent facilities in event of fireh) Security of installations from outside hazards

i) Minimising danger and inconvenience to personnel and property

beyond the boundary fence.


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j) Ergonomic Factors

k) Escape access ways shall be as straight and obstruction free as

possible.l) Hazardous area classification

m) Ensuring that flammable vapour generated from one facility will

diffuse to a concentration well below the lower explosive level (LEL)

before it reaches any other facility or area where a source of ignition

may exist.

n) Providing a reasonable degree of protection (distance) against heat

radiation

2.2 Circumstances will arise where it will be difficult to adhere to the minimum

spacing requirements; e.g. where there are severe limitations on plot

availability. In such cases a reduction of minimum spacing (less than 10%) shall

only be acceptable, after agreement with PTT/CONSULTANT. Any reductions in

the proposed distances between equipment shall be subject to a Risk

Assessment or Hazard Analysis. In this case extra safety features such as

Firewalls, Sprinklers, Emergency Shutdown Facilities etc., shall be required to

be incorporated into the design in order to compensate for the reduction in the

distances between the equipment. Such reductions shall not be made without

prior reference to PTT/CONSULTANT.

2.3 Other factors may require spacing greater than minimum recommendation of

this Standard. In this category consideration should be given to:

Proximity of adjacent property and the consequential environmental and public

relations effects.

Special process hazards, which may necessitate increased spacing.

Special plant maintenance or installation considerations

Future development plans both inside and outside the boundary fence.

Topographical features of site and direction of prevailing winds

Political security factors.

Special hazard zoning plans for existing plant areas.

3.0 DEFINITIONS

The following definitions are used throughout the standard.

3.1 Flash Point

The flash point is the lowest temperature at which a product gives off sufficient

vapour to form a mixture with air that can be ignited by a flame or spark.

3.2 Auto Ignition Temperature (AIT)


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The auto-ignition temperature is the temperature at which a product will burn

without application of any other form of ignition.

The AIT of most petroleum products is between 250C and 500C. In general

the AIT of petroleum hydrocarbons decrease with higher boiling fractions

whereas flash points increase.

3.3 Sources of Ignition

Possible sources of ignition include the following:

3.3.1 Electrical

Sparks or arcs may occur when current carrying contacts are separated or

through static electricity discharge.

3.3.2 Naked Lights

E.g. fired heaters, fires, smoking, hot work, gas welding, etc.

3.3.3 IC Engines

Spark-ignition systems, exhaust hot spots.

3.3.4 Spontaneous Combustion

Pyrophoric materials, vapour leakage at temperatures above AIT.

3.3.5 Frictional Ignition

Grit blasting, power tool grinding, mechanical failure of rotating machinery.

3.3.6 High Temperature Surfaces

Transfer lines, HP steam lines, and other hot surfaces.

4.0 STANDARDS AND GUIDES

Philosophy on plant layout is contained within various standards and guides,

including;

SPC-0804.02-50.01 Design Instruction for Piping Arrangement.

Noise Control Eng. Std.

Institute of Petroleum Model Codes of Safety Practice, Part 3

LP GAS Association Code of Practice 1

Institute of Petroleum Model Codes of Safety Practice, Part 9, LPG


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Area Classification Code for Petroleum Installations,(IP15) Model Code of

Safe Practise in the Petroleum Industry Part 15

NFPA-30 (Flammable & Combustible Liquids Code)

NFPA-58 (Storage and Handling of LPG)

NFPA-59 (Storage and Handling of LPG)

NFPA-59A (Storage and Handling of LNG)

Fire Fighting Systems

European Standard EN 1473, Installation and equipment for LNG Designof onshore installations.

European Model Code of Safe Practices in the Storage and Handling of

Petroleum Products. Part 1, Operations.

API Standard 2510 Design and Construction of LPG Installations

Thai Fuel Oil Storage Act 2474

Announcement of the ministry of liquid petroleum gas containment

Note: Reference should be made to these documents when producing the

optimum layout of the relevant plant facilities.

5.0 SPACING OF UNITS AND AREAS

Fig.1 Show a typical overall PLOT PLAN

5.1 Process Unit

A process complex consists of a combination of plants, each carrying out a

specific processing duty. These plants are defined as PROCESS UNITS.

Equipment items within the process unit limits are referred to as on-site

equipment. On-site Spacing Chart, Fig. 4, gives the recommended spacing

between these items of equipment.

Equipment limits are determined by an imaginary line drawn around the outer

edge of equipment within the Process Unit.

5.2 Process Area

Several process units may be combined to form a PROCESS AREA. These unitsmay be integrated, i.e. by no spacing between units other than basic equipment

spacing, or may be laid out as separate units with spacing between equipment

limits (as defined above) based on fire fighting access, process hazard or

separate shut-down requirements; depending on overall plant philosophy.


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5.3 Process Block

A number of process areas may be combined to form a PROCESS BLOCK. Fig.2 indicates an example of a Process Block showing the arrangement of a

Process Unit (integrated and separate) and Process Areas within the block. The

basic minimum spacing between Units and Areas are given on Fig. 2.

5.4 Tankage Block

Fig. 3 shows the basic minimum spacing between bunded areas for a

TANKAGE BLOCK.


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Fig. 1 Typical Overall Plot Plan.

FIRE TRAINING

EFFLUENT

TREATMENT.UTILITY AREA

STORM

DRAIN

PROCESS

UNITS

ADMIN

BLDG.

FUTURE PROCESS UNITSFUTURE EXPANSION

CRUDE OIL

TANKAGE

GRADE

PIPETRACK

LPG

SPHERES

INTER-

MEDIAT

TANKS

PROCESS

BLOCK

FUTURETANKAGE

TANKAGE

BLOCK-PRODUCT

STORAGE

ELEVATED

PIPERACK

FUTURE

UTILITY

AREA

REFINERY

BOUNDARY

FENCE LINE

GATE

HOUSE


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Fig. 2 Example of a Process Block

Shows the process block divided into areas: and an area divided into units. Also showthe dimensions of the clearances required.

10m

C

10m

B

EQUIPT.

LIMITS

ALL

EQUIPT

WITHIN

LINES

ACCESS

EQUIPMENT LIMIT

SINGLE LARGE UNIT

INTEGRATED UNITS

(No Physical Separation)

AB

C

ACCESS

SEPARATE

UNIT

10m 50m 50m 50m15m 15m

10m

80m

80m

60m

30m

30m

A

RESTRICT

TO 300m

(approx)

UNIT

LIMIT

SEPARATE

UNIT

UNIT

LIMIT

C

EQUIPT.

LIMITS

PROCESS AREA


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Fig. 3 typical Tankage Block

Dimensions are from the inside of the top bund wall. Bund should not be less than 15

m. from the outer boundary of the installation or the protection belt. This is to allow

for an access for firefighting and also to create a safe distance from the boundary.

30m 30m

ACCESS

ROAD

30m


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Fig. 4 On Site Spacing Chart

This chart to be used with On-site spacing guide.

Note: All distances in metres

N.A. Not applicable.

X Provide spacing based on access for operation and maintenance.

Y As required see On-site spacing guide.

Basic spacing is the recommended distance required between a given facility and

other general processing equipment. This spacing is not required between items

in similar service, (i.e. pumps and spare etc).

See notes in section 7.1: On-site spacing guide.

7.5 7.5 7.5 7.5

3 4.5 4.5 1.5 4.5

7.5 7.5 7.5 N.A. 15 N.A. 7.5 7.5 7.5 7.5 X X X N.A. 7.5 X X

EMERGENCY VALVES FOR SHUT-OFF,

ISOLATING, SNUFFING ETC

X

EMERGENCY VALVES ETC

X

7.5

4.5

4.5 4.5 1.5 3 6 4.5 3 1.5 4.5 4.5 X 7.5 4.5 4.5

ON SITE PIPE RACKS

MAIN EQUIPMENT STRUCTURES

X

15

15

30

X

10.5

4.5 4.5 X

15 15 15

22.5 X 4.5 X X 15 15 4.5 3 7.5 X X 30

22.5 15 15 15 15 15 15 15 15 15 X X X

15 15 15 22.5 15 15 15 15 15

30 30 30 30 30 30 30 30 30

4.5 4.5 X X X 4.5 X X 4.5

4.5 7.5 10.5 22.5 15 4.5 10.5 10.5 7.5

15 15 15 15 15

30 30 30 30 30

X 4.5 X X X

15 4.5 10.5 X X

15

X X

15 X

X X X

X X

X

7.5 7.5 7.5 7.5 22.5 15

3 4.5 7.5 3 22.5 7.5

4.5 4.5 7.5 4.5 22.5 15

7.5 7.5 7.5 22.5

4.5 3 3 15

4.5 4.5 4.5 7.5

15 15 15 15 22.5 15 15 15 15 30

15 4.5 7.5 15 22.5 15

3 4.5 7.5 3 22.5 7.5

1.5 4.5 7.5 1.5 22.5 7.5

7.5 15 15 Y

4.5 3 X

4.5 1

15 7.5 7.5

15 4.5 1

15 1.5

X

X

4.5 4.5 7.5 4.5 22.5 15

7.5 15 15 7.5 22.5 X

22.5 22.5 22.5 22.5 10

1

1.5 4.5 7.5 1.5

7.5 7.5 1.5

4.5 1.5

3

ELECTRICAL SUBSTATION

UNIT CONTROL HOUSE

CENTRAL CONTROL HOUSE

EQUIPMENT HANDLING NON-

FLAMMABLES

COMPRESSOR DRIVERS (OTHER THAN

STEAM OR MOTOR)

GAS COMPRESSORS AND EXPANDERS

HANDLING FLAMMABLE MATERIALS

PUMPS HANDLING FLAMMABLE

MATERIALS

PUMPS ABOVE AIT

COOLING TOWERS

FIRED HEATERS

AIR FIN COOLERS

EXCHANGERS OPERATING BELOW AIT

EXCHANGERS OPERATING ABOVE AIT

BLOWDOWN AND DISENGAGING DRUMS

ON-SITE PRESSURE STORAGE VESSEL

DRUMS

REACTORS ABOVE AIT INTERNALLY

INSULATED

REACTORS ABOVE AIT EXTERNALLY

INSULATED

N.A.

15

15

30

X

10.5

7.5

3

4.5

15/30

15

3

1.5

4.5

7.5

22.5

1.5

7.5

4.5

1.5

RT1

RR1

RS1

RQ1

RP1

RO1

RN1

RM1

RL1

RK1

RJ1

RI1

RH1

RG1

RF1

RE1

RD1

RC1

RB1

RA1

RU1

RV1

22.5

ITEM

REF.

BASIC SPACING

TOWERS


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6.0 ON SITE SPACING

The recommended spacing for on-site equipment is indicated in On-site

Spacing Chart Fig. 4.

The information on this chart is supplemented by explanatory notes which are

contained in Section 7.1 On-Site Spacing Guide.

It is essential that reference is made to Section 7.1 when using On-Site

Spacing Chart Fig. 4.

Against each type a basic spacing dimension is quoted. This basic spacing is

the recommended distance in metres between the item and other general

process equipment. The recommended spacing between different items is

given at the intersection of the horizontal line for one item and the vertical linefrom another. In general, this shall be the greater of the basic spacing

dimensions for the two items. Explanatory notes can be found in Section 7.1.

The spacing between two similar items is given in the first box adjacent to the

item. Note that basic spacing is not required between items in the same

service.

6.1 On-Site Spacing Guide(Use with on-site spacing chart Fig. 4)

6.1.1 Ref.: RA1 Towers

(Basic Spacing 1.5 metres)

The basic spacing of 1.5 metres provides access for operation and

maintenance. The distance between two towers is twice the basic dimension.

This provides some additional access for fire fighting and clearance for non-

coincidental platforms.

6.1.2 Ref. RBI Reactors

(Above AIT externally insulated) (Basic spacing 4.5 metres)

The basic spacing of 4.5 metres provides access for fire fighting and minimises

damage to other equipment. The external insulation protects the reactor shell

from fires on other equipment.

Reactors may be grouped together; in which case operational and maintenance

access of 1.5 metres between shells is satisfactory.

Reactors operating below AIT may be regarded as drums, i.e. drum spacing

recommendations will apply (see Ref. RD1).

Spacing from Ref. RF1 is in excess of the greater basic dimension as theReactor is regarded as high-risk equipment.

Since the Reactor is operating above AIT, other sources of ignition are not a

spacing consideration and basic reactor spacing of 4.5 metres will apply, e.g.

items Ref. RJ1 and R01.


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6.1.3 Ref. RC1 Reactors

(Above AIT internally insulated. Basic spacing 7.5 metres)

The basic spacing of 7.5 metres provides access for fire fighting, minimises

damage to other equipment in event of reactor fire, and protects exposed shell.

N.B. Internally lined reactor shells are more susceptible to fire damage than

unlined vessels. Reactors may be grouped together; in which case operational

and maintenance access of 1.5 metres between shells is satisfactory.

Reactors operating below AIT may be regarded as drums, i.e. drum spacing

recommendations will apply (see Ref. RD1).

Spacing from RF1 is in excess of the reactor after basic dimension as the

reactor is regarded as high-risk equipment.

Since the reactor is operating above AIT, other sources of ignition are not a

spacing consideration, basic reactor spacing of 7.5 metres will apply, e.g. items

RJ1/R01.

Spacing from Refs. RP1, RT1, RU1 these items are not regarded as fire

hazardous the spacing of 4.5 metres will give these items protection in the

event of reactor fires.

6.1.4 Ref. RD1 Drums


The basic spacing of 1.5 metres access for operation and maintenance. Spacing

from RU1 is the basic drum spacing as the pipe rack is not considered fire

hazardous. Drums should not be located under pipe racks.

6.1.5 Ref. RE1 On-site Pressure Storage Vessels


The basic spacing of 22.5 metres minimises exposure of unit equipment to a

potential source of severe fire, and blast damage in the event of an explosion.

Pressure storage in on-site locations shall be avoided wherever possible.

It is sometimes necessary, e.g. in solvent propane dewaxing and deasphalting

units to provide pressure storage facilities on-site; in such instances the

inventory shall be held to a minimum and the storage vessel located at the unit

battery limit and as far as possible from fired heaters and other source of

ignition.

For pressure storage vessels, in the same service provide a minimum of onediameter between shells for operational and maintenance access.

Spacing from RU1 pipe racks is not considered as fire hazardous- spacing of

4.5 meters affords protection to these items in the event of storage vessel fire.


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6.1.6 Ref. RF1 Blow-down and Disengaging Drums

(Basic spacing 7.5 metres)

The basic spacing of 7.5 metres provides protection to the Drum in the event of

fire within the unit.

For high-risk equipment the spacing shall be increased to 15 metres. High risk

equipment includes reactors, exchangers and pumps, operating above AIT, fired

heaters, gas compressors and expanders, and their drivers, e.g. items Ref. RB1,

RC1, RG1, RL1, RN1, R01.

Spacing from Ref. RU1 pipe racks are not regarded as fire hazardous

spacing of 4.5 metres affords protection to the pipe rack in the event of

blowdown drum fire.

6.1.7 Ref. RG1 Exchangers

(Operating above AIT) (Basic spacing 4.5 metres)

The basic spacing of 4.5 metres minimises damage to other equipment in event

of fire. Exchangers operating above AIT are high-risk items with greater

probability of fire than for exchangers operating below AIT.

Exchangers above AIT in the same service, i.e. connected by a common

process stream, may be spaced 1.0 metres apart; for other exchangers basic

spacing of 4.5 metres shall apply.

Spacing from Ref. RJ1 since the fluid in the exchanger is already above its

AIT, the fired heater, in this case, does not represent a source of ignition.

However, a heater fire is considered likely to be more severe than other plant

fires, so spacing greater than basic is applied to minimise damage to the

exchanger in the event of a heater fire.

Spacing from Ref. R01 since the fluid in the exchangers is above its AIT, the

compressor driver does not represent a source of ignition. Therefore,

exchanger basic spacing of 4.5 metres applies.

Spacing from RF1 is in excess of the greater basic dimension as the exchanger

(above AIT) is regarded as a high-risk item.

Spacing from ref. RP1 protects equipment from a high fire risk system.

6.1.8 Ref. RH1 Exchangers

(Operating below AIT) (Basic spacing 1.5 metres)

The basic spacing of 1.5 metres provides access for maintenance and

operation. There are no limitations on spacing exchangers from pipe racks exchanger spacing applies.

6.1.9 Ref. RI1 Air Fin Coolers


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(Basic spacing 3 metres)

Air fin coolers by virtue of their design and operations are particularly vulnerableto fire hazard.

For this reason grade mounted units isolated from other equipment are

preferred. However, because of restrictions on area availability, it is common

practice to mount air fin coolers on top of the pipe rack. In such cases

consideration shall be given to the following:

Air fin coolers shall not be mounted over pumps, compressors, drums or heat

exchangers, containing flammable materials.

There shall be no flanges or valves in any hydrocarbon lines on the rack

beneath an air fin cooler.

Horizontal spacing requirements of on site spacing chart, Fig.4, shall be met.

Support legs for the air fin cooler shall be fireproofed in accordance with the

relevant Project Engineering Standard.

Access shall be provided for tube bundle removal by mobile equipment.

The basic spacing of 3.0 metres (horizontal) minimises exposure to fire hazard

air fins are more vulnerable to fire damage than shell and tube exchangers.

Ref. RU1 the basic spacing of 3.0 metres is applicable to grade mounted air

fin coolers only.

6.1.10Ref. RJ1 Fired Heaters


A fired heater by its nature is a permanent source of ignition while operating. A

heater fire is likely to be of maximum severity. The basic spacing of 15 metres

separates equipment handling flammable vapours from a permanent source of

ignition and affords protection in the event of a major heater fire. Heater

location will sometimes be predetermined by the requirement of grouping to a

common stack with heaters from other process units.

Where such restrictions are not applied, the heater location shall be selected on

the windward side of the unit with reference to the prevailing wind, close to the

battery limit and as far as practicable from other equipment. Consideration

shall also be given to the proximity of plant and equipment outside the unit

battery limit.

When the heater has an individual stack, the top of the stack shall be at least 3

metres higher than equipment within a horizontal distance of 15 metres and atleast 3 metres higher than any operating platform within a horizontal distance

of 65 metres.


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Ref. RJ1 - If all heaters in a group shutdown together at plant turnaround,

spacing between shells can be for normal maintenance only. If heaters are

required to shutdown individually, spacing of 7.5 metres between shells isrequired for LP operation (less than 7 kg/cm2g) and 15 metres between shells

for HP operation (7 kg/cm2g and above).

Refs. RB1, RC1, RG1, RL1 are items operating above their AIT and in these

cases the fired heater is not considered to be the primary source of ignition,

spacing is based on affording protection in the event of heater fire.

For reformer heater/reactor installations, where vapour only is present in heater

tubes and reactors, spacing may be further reduced to 3 metres in the case of

Ref. RB1 and 5 metres in the case of Ref. RC1.

Ref. RN1 the compressor area is regarded as a special risk area in view of the

potential release of large vapour quantities. Spacing greater than the basic

dimensions are required.

Ref. R01 the compressor driver is not considered a source of ignition in this

case. The spacing of 7.5 metres minimises damage to the compressor driver in

the event of heater fire.

Ref. RP1 a spacing of 4.5 metres minimises damage in the event of the

heater fire. For equipment higher than 3 metres, spacing shall be increased to

7.5 metres from heaters with liquid in their tubes. Reduced spacing is

permitted because there is no flammable material release in the event of

damage.

Ref. RU1 because of severity of heater fire, spacing to pipe racks is greater

than basic.

N.B. This does not apply to heaters own pipe rack

6.1.11 Ref. RK1 Cooling Towers

(Basic spacing 15 and 30 metres)

Basic spacing of 15 metres applies to equipment lower than the cooling tower;

basic spacing of 30 metres to equipment higher than the cooling tower.

The cooling tower becomes a source of hazard in the event of tube failure in a

water cooler. Basic spacing provides for dispersion of hazardous vapours,

minimises corrosive effects of spray impingement and visibility problems from

exhaust plume.

The cooling towers shall be located on the leeward side of a process unit with

reference to the prevailing wind.

Ref. RU1 the factors above are not consideration in the case of a pipe rack.Pipe rack basic spacing will apply.


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Ref. RU1 is not a hazard producing item. The basic spacing of 4.5 metres

provides protection in the event of compressor fire.

6.1.15Ref. R01 Compressor Drivers(Other than steam or motor)


Basic spacing is not applicable between Compressor and driver. Gas turbine,

gas engine or internal combustion engine drivers are sources of ignition. Basic

spacing of 10.5 metres affords safe spacing from a source of ignition.

For items RB1, RC1, RG1, RL1, which are operating above AIT, the driver is not

considered to be the primary source of ignition. The basic spacing for these

items therefore applies.

Ref. RJ1 spacing of 7.5 metres protects driver in event of heater fire.

Ref. RF1 spacing greater than basic provides additional protection to critical

item.

Ref. RU1 the pipe rack is not a hazard rack basic spacing applies.

6.1.16Ref. RP1 Equipment Handling Non Flammables

(Spacing provided for operational and maintenance access)

Ref. RB1, RC1, RG1, RJ1, RL1 spacing of 4.5 metres provides protection to

equipment in the event of fire at likely sources of ignition.

6.1.17Ref. RQ1 Central Control House


Basic spacing of 30 metres affords protection to personnel and critical control

equipment from plant fire or explosion hazard. Consideration shall be given in

special circumstances to blast-resistant design of building.

Ref. RU1 on site pipe racks shall not be nearer than 30 metres to the Control

House. Provided lines are fully welded with no valves or flanges, a pipe rack

may be brought to 7.5 metres from one side only of a central control house.

6.1.18Ref. RR1 Unit Control House


The location of a unit control house is obviously less critical than a centralcontrol house. It should be located at the battery limit adjacent to a roadway.

Basic spacing minimises risk to personnel and equipment in the event of a unit

fire.


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Ref. RU1 pipe rack basic spacing applies provided lines are fully welded

without valves or flanges.

6.1.19Ref. RS1 Electrical Sub-station


Electrical sub-stations are located close to the battery limit and near to a

roadway. The basic spacing is fixed by Area Classification considerations and

provides protection to the electrical equipment in the event of unit fire.

Ref. RU1 pipe racks do not present a major hazard. Basic rack spacing

applies.

6.1.20Ref. RT1 Main Equipment Structures

(Basic spacing not applicable)

Sufficient spacing shall be allowed from ignition sources of high-risk RC1 items

to prevent damage to structure in event of fire or explosion. Items RB1, RC1,

RE1, RG1, RJ1, RL1, RN1 are in this category. In most other cases the

equipment in the structure will govern its location with respect to other

equipment.

6.1.21 Ref. RU1 On-site Pipe Racks


Pipe rack basic spacing gives protection to the pipe rack in the event of

equipment fires within a process unit. Items Ref. RB1, RC1, RE1, RG1, RK1,

RN1 and R01 are located on this basis.

Item Ref. RJ1 fired heater is a possible source of a major fire. Spacing

greater than basic is required in this case.

N.B. This limitation does not apply to the pipe rack serving the heater area.

The pipe rack in itself is not considered highly hazardous. In general equipment

which is not hazardous may be located on access and operability considerations

relative to the pipe rack. Items Ref. RA1, RD1, RH1, RI1 (grade mounted) are

in this category.

In special cases where the hazard from the pipe rack shall be minimised, fittings

and flanges which could be sources of leakage shall be eliminated from the pipe

rack in the vicinity, e.g. from pipe racks under air fin exchangers and from pipe

racks in the vicinity of control houses, i.e. items RI1, RQ1 and RR1.

Pumps are also considered as a special case as, for layout purposes, access and

operability, it is usual to have pumps in close proximity to the pipe rack, e.g.items Ref. RL1 and RM1 spacing is horizontal distance from pump stuffing

box to edge of pipe rack.


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6.1.22 Ref. RV1 Emergency Valves for Shut-off, Isolation, Snuffing, etc.


The basic spacing is the distance between the emergency valve and the

equipment it controls. It can be located adjacent to other equipment.

Ref. RE1 and RJ1 are exceptionally hazardous items. The basic spacing for

these items there applies.

Where it is necessary for reasons of plant layout to locate emergency shut-off

valve manifolds closer to a heater than 15 metres, a fire wall shall be provided

between the manifold and the heater at a minimum distance of 7.5 metres from

the heater.

6.1.23 Roads of width 6 metres or more

Maintain a minimum of 10m between roads and any hydrocarbon containing

equipment.


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Fig. 5 Off-Site Spacing Chart

30

45

15

45 30 60 45 45 45 45 45 4.5

45 45 45 45 45 45 45 45 4.5

7.5 15 15 7.5 7.5 7.5 45 N.A. 4.5

45 45 30 60 15

45 45 30 60 30

45 N.A. 15 N.A. N.A.

30 N.A.

X

30 7.5 30 60 7.5 7.5

30 45 15 15 45 45

45 X 30 60 X X

7.5 60 45 7.5

30 45 15 4.5

X 45 45 4.5

45 60 30 60 45 45 45 45 45 4.5

6 15 4.5 X 7.5 4.5

45 60 30 60 45 45

45 45 45 60 45 45

4.5 45 15 N.A.

45 45 N.A.

45 N.A.

60 N.A. 45

15 45 X

45 N.A.

N.A.

15

30 X 15 60 X X

30 X 15 60 X N.A.

X X 45 60 X

X

60 60 60 N.A.

30 45 X

30 X

X

FACILITIES FOR HEAT SENSITIVE

MATERIALS EG TEL. & TML.

MAIN EFFLUENT TREATMENT

PLANT RAIL FACILITIES

RAILWAY MAIN LINES

MAJOR PUMP AREAS

BOUNDARY FENCE

PROCESS AREAS

MAJOR OFFSITE PIPE TRACKS

LOADING RACKS FOR LOW FLASH

PRODUCTS

FIRE TRAINING AREA

MAIN FIRE WATER PUMPS

FIRE STATION

MAIN ELECTRICAL SUB-STATIONS

JETTIES (LOADING ARM MANIFOLD)

COOLING TOWERS

BUILDINGS, MAIN OFFICES, WORK-

SHOPS, LABORATORIES, ETC

30

45

15

60

15

45

45

4.5

45

45

45

45

45

60

15/30

45

30

RR2

RQ2

RP2

RO2

RN2

RM2

RL2

RK2

RJ2

RH2

RG2

RF2

RE2

RD2

RC2

RB2

RA2

This chart to be used with Off-site spacing guide.

Note: All distances in metres

N.A. Not applicable

X Provide spacing based on access for operation and maintenance.

Basic spacing is the recommended distance required between a given facility and

other general processing equipment.

See notes in section 8.1: Off-site spacing guide.

FACILITY

REF.

BASIC SPACING

BOILER HOUSES AND POWER

STATIONS


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7.0 OFFSITE SPACING

Facilities outside the confines of a Process Block, e.g. boiler houses and powerstations, administration offices, workshops, effluent treatment, flare stacks,

jetty and rail loading, blending facilities etc., are referred to as off-site

facilities.

It is customary to combine the utility type facilities, e.g. steam generation,

water treatment, plant air etc., within a utility area or block.

Effluent treatment, flare and similar high hazard off-site facilities are generally

located remote from process facilities, utility areas and administration areas.

Spacing of flare stacks requires special consideration based on relief loads andthermal radiation levels. Reference shall be made to the Process Engineer.

The recommended spacing off-site equipment is indicated in Off-site Spacing

Chart, Fig. 5.

The information on this chart is supplemented by explanatory notes contained

in Section 7.1 Off-site Spacing Guide.

It is essential that reference is made to Section 7.1 when using Off-site

Spacing Chart, Fig. 5.

Against each item a basic spacing dimension is quoted. This basic spacing is

the recommended distance in metres between the item and other

equipment/facilities. The recommended spacing between different items is

given at the intersection of the horizontal line from one item and the vertical line

from another.

In general, this shall be the greater of the basic spacing dimensions for the two

items, otherwise explanatory notes can be found in Section 7.1.

The spacing between similar equipment/facilities is given in the first box

adjacent to the item.

7.1 Off-site Spacing Guide

(Use with off-site spacing chart Fig. 5)

7.1.1 Ref. RA2 Boiler Houses and Power Stations


The basic spacing protects critical equipment from fire or explosion in process

equipment.

Ref. RB2 buildings are not considered hazardous to boilers and generating

plant and vice versa. Therefore, spacing less than basic for buildings is

acceptable.


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Ref. RK2 spacing protects pipe track from possible fire in boiler house.

Ref. RO2 railway main lines are not at risk from facilities and do not present arisk to facilities. Boiler basic spacing applies.

Ref. RP2 rail sidings present a minimum risk to facilities. Siding basic spacing

applies.

Note that steam generators forming an integral part of a process unit are

considered as fired heaters. In such cases, on-site basic spacing will apply.

7.1.2 Ref. RB2 Buildings, Main Office Block, Workshops, Laboratories etc.


The basic spacing protects personnel from fires and explosions in process

equipment.

For high hazard process equipment, spacing in excess of basic is applied.

Items Ref. RD2, RJ2, RL2 fall into this category.

Items Ref. RA2, RK2, RO2, RP2 are not considered high-risk items. Spacing

less than basic building space is applied.

7.1.3 Ref. RC2 Cooling Towers

(Basic spacing 15 metres and 30 metres)

Two basic spacing are given for Cooling Towers.

The lower basic spacing is for equipment that is lower than the cooling tower.

The higher basic spacing is for equipment that is taller than the cooling tower

and where it is necessary to minimise the corrosion, visibility and ice formation

problems, resulting from the impingement of the cooling tower exhaust plume.

A cooling tower can become a source of hazard due to release at atmosphere of

flammable vapours, caused by tube failure in water cooled exchangers. The

higher basic spacing distance is considered adequate for dispersal of these

vapours.

Spacing greater than cooling tower basic is applied from highly hazardous

sources, e.g. items Ref. RD2 and RH2.

Items Ref. RF2, RG2 and RO2 do not present a hazard to these cooling towers.

Cooling tower basic spacing is therefore applied.

Items Ref. RJ2 and RL2 are possible sources of fire. Higher cooling tower basicspacing is applied to these items.

Items Ref. RM2 and RO2 do not present a hazard to the cooling tower. Cooling

tower higher basic spacing is applied for environmental considerations.


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Item Ref. RK2 the cooling tower is not considered to be at risk from the pipe

track. Pipe track basic spacing is applied.

7.1.4 Ref. RD2 Jetties

(Loading arm manifold basic spacing 60 metres)

The basic spacing protects facilities from fires at loading manifolds or on

tankers and vice versa.

Items Ref. RN2, RP2, RQ2 are not considered as sources of hazard. Basic

spacing for these items will apply.

7.1.5 Ref. RE2 Main Electrical Sub-stations


The basic spacing protects electrical equipment from explosion or fire in

process areas. By using blast resistant construction, this basic spacing may be

reduced.

Items Refs. RK2, RO2, RP2 are not considered as major sources of hazard.

Spacing less than basic is allowed.

7.1.6 Ref. RF2 Fire Station


The basic spacing provides protection to the fire station and equipment in the

event of fire in the process areas.

Items Ref. RA2, RC2, RK2, RO2 and RP2 are not considered as major sources

of hazard. Spacing less than basic is allowed.

Items Ref. RB2, RE2, RG2 and RM2 are not hazardous to the fire station.

Location is determined by access and maintenance considerations.

7.1.7 Ref. RG2 Main Fire Pumps


The basic spacing provides protection to prevent loss of pumps from fire

exposure.

Items Ref. RA2, RC2, RK2, RN2, RO2 and RP2 are not considered sources of

major hazard. Spacing less than basic is allowed.

Items Ref. RB2, RE2, RF2 and RM2 are not hazardous to fire pumps. Location isdetermined by access and maintenance considerations.


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7.1.8 Ref. RH2 Fire Training Area


The basic spacing protects vulnerable process equipment from a source of

ignition. Spacing also allows smoke dispersal.

7.1.9 Ref. RJ2 Loading Racks


The basic spacing is considered adequate for the dispersal of spillage or vapour

releases. During unloading it also protects the equipment in the event of fires

at process areas and vice versa.

In locating main loading racks, consideration shall be given to access from

outside and to minimising the flow of traffic through process areas.

Spacing shall be sufficient to allow the safe manoeuvring of road tankers and

for rail sidings where applicable.

Items Ref. RC2, RK2 and RN2 are not considered hazardous with respect to the

loading area. Spacing less than loading rack basic is acceptable in these

instances.

For item Ref. RB2 spacing greater than basic is applied to reduce hazard to

personnel.

7.1.10Ref. RK2 Major Off-site Pipe Tracks


The basic spacing of 4.5 metres minimises hazard to off-site piping in the event

of fires at major plant areas.

For items Ref. RC2, RF2, RL2, RM2, RN2, RP2, RQ2 and RR2, this criterion

applies.

For items Ref. RA2, RB2, RE2, RH2, RJ2 and RO2 greater spacing is applied for

commodity criticality or personnel hazard requirement.

7.1.11Ref. RL2 Process Areas


The basic spacing minimises damage to other areas or equipment in the event

of fire or explosion in the process area and vice versa.

For item Ref. RB2 spacing greater than basic is applied to reduce hazard topersonnel.

Items Ref. RC2, RK2 and RN2 are not considered at high hazard from process

areas. The basic spacing for these items is therefore applied.


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A process to process area spacing of 15 metres is considered sufficient to

permit independent shutdown at turnaround.

In the case of light end units this shall be increased to 25 metres. Where

several process units are integrated, the internal spacing shall be based on

maintenance, operational and fire fighting access.

7.1.12Ref. RM2 Boundary Fence


The basic spacing provides protection to personnel and property outside the

boundary fence in the event of explosion or fire. It also protects the facilities

inside the fence from external hazard.

Item refs. RC2 and RK2 are reduced hazard items. Spacing less than the basic

boundary spacing is acceptable in these instances.

Item refs. RB2, RE2, RF2 and RG2 are not hazardous. Spacing from boundary

fence is based on access or environmental consideration.

7.1.13Ref. RN2 Major Pump Areas


The basic spacing affords protection to pump areas in the event of fire or

explosion in process facilities and allows access for fire fighting.

Pump areas, because of their low inventory, do not present a major hazard to

other equipment.

Spacing less than basic item spacing is therefore permitted from these items,

e.g. items Ref. RD2, RG2, RJ2, RL2, RO2 and RQ2.

7.1.14Ref. RO2 Railway Main Lines


The basic spacing protects personnel and railway property from fire or

explosion inside plant.

Items Ref. RA2, RC2, RJ2 and RN2 present a reduced hazard to railway

property. Spacing less than basic is permitted in these cases.

7.1.15Ref. RP2 Rail Sidings


A rail siding can be considered as a source of ignition from a locomotive engine.The basic spacing protects flammable equipment or sources of vapour emission

from this hazard.

Items Ref. RC2, RD2, RN2 and RR2 fall in this category.


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Non-hazardous items may be located at less than the basic spacing. Items Ref.

RB2, RE2, RF2, RG2 and RK2 fall in this category.

For item Ref. RQ2, additional spacing is required to permit dispersal of vapours.

7.1.16Ref. RQ2 Main Effluent Treatment


A basic spacing of 45 metres from process areas or other sources of ignition

allows for dispersal of vapours, which are likely to be emitted at a separator.

Items Ref. RA2 to RJ2, RL2, RM2 and RR2 fall in this category.

Lower risk facilities, not representing a source of ignition, may be located not

less than 30 metres from a separator. Items Ref. RN2 and RP2 fall in this

category.

Item Ref. RK2, off-site pipe tracks, is a minimum risk item. Its basic spacing

applies.

7.1.17 Ref. RR2 Facilities for Heat Sensitive Materials


Heat sensitive materials are liable to decomposition explosions on prolonged

exposure to heat. The basic spacing of 30 metres protects the facilities from

such exposure.

Items Ref. RK2 and RP2 are not sources of fire. Spacing less than basic 30

metres will be acceptable in these instances.

8.0 TANKAGE

This section gives basic guidance for the spacing and bund capacities ofstorage tanks, storage spheres and cylinders. In cases where a conflict may

occur between this document and the Thai Fuel Storage act B.E. 2474, then

that Act shall always take precedence.

For specific spacing direction, particularly for LPG and LNG duties, refer to the

relevant listed standard(s).

Other types of bulk storage, e.g. underground caverns, are not covered by this

standard.

8.1 Flammable Liquids

Petroleum products by their nature are potentially hazardous, the degree of

hazard being directly related to their volatility and flash point.


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These are classified:

Class 0 Liquified petroleum gasClass I Liquids having flash points below 21C

Class II (1) Liquids with flash points from 21C to

55C stored below flash point

Class II (2) Liquids with flash points from 21C to

55C stored at or above flash point

Class III (1) Liquids with flash points from 56C to

100C stored below flash point

Class III (2) Liquids with flash points from 56C to

100C stored at or above flash point

Unclassified Liquids which have flash points above

100C

8.2 Types of Tankage

8.2.1 The type of tank used to store a particular product is generally specified by

Clients requirements. In the absence of such requirements, type selection

should be referred to the Process Design Co-ordinator.

8.2.2 Fixed or Cone Roof Tanks (CR)

For the storage of Class III (1) and Class III (2) and Unclassified products. Other

classes of product may be stored in this type of tank, provided that the vapour

pressure at storage temperature is less than atmospheric pressure (e.g. refrig.

atmosphere storage of LPG/LNG).

8.2.3 Floating Roof Tanks (FR)

For the storage of Class II (1) and Class II (2) flammable products in the middle

flash point range.

8.2.4 Spheres and Cylinders (SP and CYL)

For the storage of Class 0 and Class I highly flammable products, which have

flash points below 21C, e.g. pressure storage of LPG products.

8.2.5 Table 1

This table gives typical examples:

Product Type of Tank or Vessel Class Comments

C3 CYL 0 Pressure Storage

C4 SP 0 Pressure Storage

C3 CR 0 Refrig. Atmos. Storage

C4 CR 0 Refrig. Atmos. Storage

LPG/LNG CR 0 Refrig. Atmos. Storage

Benzene FR I

Xylene FR I


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Product Type of Tank or Vessel Class Comments

Reformate FR I

Gasoline FR INaphtha FR I

Kerosene FR II (1)

Jet Fuel FR II (1)

Crude Oil FR II (2) Boil/roll Over

Tendencies

Gas Oil/Diesel FR III (1)

LFO CR III (2)

MFO CR III (2)

HFO CR III (2)

Heavy Oil/Residue CR III (2)

Asphalt/Bitumen CR UnclassifiedNote: Certain produce classifications may change if operational temperatures

are increased.

8. 3 Definitions

8.3.1 Bund or Firewall

A wall of predetermined height constructed of concrete, earth, or any other

suitable material and designed to confine spillage of tank contents.

8.3.2 Bunded Area

An area bounded by bund walls to confine spillage.

8.3.3 Exposed Bunded Area

The nett effective area bounded by a bund wall after the deduction of tank

areas contained within the bunded area.

8.3.4 Secondary or Intermediate Bunds

As for bund above, but usually no higher than 600mm in order to contain local

spillage within a sub-area of the main bunded area.

8.3.5 Bund Capacity

The volume in cubic metres that can be contained within the exposed bunded

area.

8.3.6 Tank Group

A number of tanks contained within a common bund.

8.3.7 Small Tanks

A tank of 10 metres diameter or less and capacity of 8000 cubic metres of

water or less is deemed to be a small tank.


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8.4 Grouping and Spacing of Tanks

8.4.1 It is desirable to group tanks for the storage of the same products in one groupwithin a bund area, subject to the prescribed limitations of the bunded capacity.

8.4.2 It is desirable that LPG or other liquefied flammable gases should be stored

remote from other products.

8.4.3 Intermediate and component tankage should be located in areas local to their

respective units where possible so that lines can be kept to a minimum length.

8.4.4 Account should be taken of the possibility of storing more than one class of

material in certain tanks or of changing the tank service at some future date.

Where future changes of service of the storage tanks are anticipated, the layout

and spacing should be for the most stringent case.

8.4.5 Wherever possible storage tanks should not be located on high ground

overlooking the facilities. This prevents spillage of flammable liquid flowing

downhill and endangering the operating plant.

8.4.6 For fire fighting reasons there should be no more than two rows of tanks

between adjacent access roads.

8.4.7 Intermediate bunds may be provided to divide the tankage into groups of a

convenient size so as to contain small spillage and act as firebreaks.

8.4.8 For Class III (1) and Unclassified petroleum stocks spacing of tanks is governed

only by constructional and operational convenience.

Note that the spacing of Class III (1) tankage from Class I, II or III (2) tankage is

governed by the latter.

8.5 Sizing of Bunds

8.5.1 Tank bund volumes shall comply with the requirements summarised below:

110% of the capacity of the largest storage vessel located within the bund

after deducting the volume up to top of bund height of all other tanks in the

same bunded area. (HSE ref.)

8.5.2 The effective height of the bund used in calculating the capacity of the

enclosure shall be the constructed height less an amount sufficient to allow for

future consolidation, settlement and possible erosion of the fill. This freeboard

allowance shall be:

150mm for 0.6 to 1.2 m effective height

225 mm for 1.5 m effective height

300 mm for 1.8 m effective height, plus 50 mm for each 0.3 m of height over

1.8 m.


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8.5.3 Bund Walls shall generally be constructed using earth embankments having a

crest of 600-mm minimum width.

8.5.4 For bunds over 1.2 m in height, stairs shall be provided for personnel.

8.5.5 In the event that there is inadequate space for construction of earthen bund

walls due to restricted site dimensions, the use of reinforced concrete retaining

walls will be permitted.


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Example 1 Cone Roof Tanks (CR)

Tanks greater than 10 metres dia. Class II and III (2) Storage

Maximum Total Tankage Capacity of Group:

60,000m3 should not be exceeded (HSE ref)

Minimum Bund Capacity:

See Paragraph 8.5

Spacing

A to suit construction and operating conditions but not less than half tank height.

B The least of (i) half the diameter of largest tank (ii) diameter of the smaller tank. -

Shall be minimum of10 metres and need not exceed 15m

C & D See Table 2

B

D C

INSIDE TOP OF

BUND

EQUIPMENT/FACILITY REFERENCE LINE. SEE TABLE 2

AA

A A

AA

B

B

B C RC R

C R C R


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REV: D2

Example 2 Floating Roof Tanks (FR) Class I, II and III (2) Storage

Maximum Total Tankage Capacity of Group

120,000m3 should not be exceeded. (HSE ref.)

Minimum Bund Capacity

See Paragraph 8.5. For tanks larger than 60,000m3 not more than 2 tanks in same

compound.

Spacing

A to suit construction and operating conditions but not less than half of tank height.

B 10 metres for tanks up to and inc. 45m dia. For tanks above 45m dia., half the

diameter of largest tank or the diameter of smaller tank - but not less than15 metres

(HSE ref.)

C & D See Table 2


B

D C

INSIDE TOP OF

BUNDAA

A A

AA

B

B

B F RF R

F R F R


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REV: D2

Example 3 Cone Roof (CR) and Floating Roof (FR) in a Common Bund Class I and II

Maximum Total Tankage Capacity of Group

No of FR Tanks x 60,000 +60, 000m3

No of Tanks in group


See Paragraph 8.5.

Spacing

A Distance equal to not less than height of tank.

B The least of (i) half the diameter of largest tank (ii) diameter of the smaller tank.

Shall be minimum of10 metres and need not exceed 15m

C & D See Table 2


B

D C

INSIDE TOP OF

BUNDAA

A A

AA

B

B

B F RF R

C R C R


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Example 4 Cone and Floating Roof Tanks not exceeding 10 metres diameter

Class I and II.

Fixed or floating roof tanks not exceeding 10 metres diameter may be grouped

together up to a total of 8000m3 and treated as one tank if grouped with other tanks.

Total overall tank capacity including other tanks in common bund not to exceed

60,000m3 if other tanks are fixed roof type, or 120,000m3 if other tanks are floating

roof type.

(HSE ref.)

Spacing

A to suit construction or operating requirements

B Half the diameter of larger tank but not less than 10 metres and need not be more

than 15 metres.

GROUP OF TANKS

NOT EXEEDING

8000m3 TREATED

AS ONE TANK (ref.HSE doc.)

INSIDE TOP OF

BUND

OTHER TANKAGE IN

COMMON BUND

A

A A

A

B

B


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REV: D2

Example 5 Refrigerated Storage (LPG Products at low temperatures) Fixed Roof

Tanks (CR) not more than 3 tanks in one compound.

No refrigerated LPG storage tank shall be located within a bund enclosing any other

tank. Each refrigerated storage tank shall have an individual bund unless spills can be

directed safely away from adjacent tanks and equipment by means of drainage and

diversion walls (as required) to an impounding basin located within the site boundary.

Double containment storage tanks do not require a bund except for local containment

of leakage from pipework, valves etc.

Total recommended maximum tank capacity for bund not greater than 60,000m3 .


See Paragraph 8.5.

Spacing:

A Minimum 30 metres

B (Dia. of large tank + dia. of small tank) divided by two.

C & D See Table 2

A

BA

A

A

B B

C R C R

D C

INSIDE TOP OF

BUND

EQUIPMENT/FACILITY REFERENCE LINE. SEE TABLE2

C R

A


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REV: D2

Example 6 Group of LPG pressure storage vessels (Class 0 products) Bullets and

Spheres

Notes:

1. Horizontal LPG tanks with capacities of 45 cu.m or greater shall not be formed into

groups of more than six tanks each. Horizontal vessels used to store LPG shall be

oriented so that their longitudinal axes do not point towards other containers,

process equipment, control rooms loading or unloading facilities, or flammable or

combustible liquid storage facilities located within the vacinity of the horizontal

vessel.

2. Grading of the area under and surrounding the vessels shall direct any leaks or

spills to a remote impoundment area. The remote impoundment area shall be

located at least 15 metres from the vessels draining to it and from any hydrocarbon

piping or other equipment.

Maximum number of vessels in any one group 6. Recommended maximum capacity

of all vessels within one group = 3 times capacity of largest vessel with in the

group.

Spacing:

A = sum of diameters of 2 adjacent tanks, but not less than 2 metres, for bullets.

(Reference IP LPG Vol1. Model Code of Safe Practice, Part 9)

D See Table 2

A A

d 1

D

d 2d 1

A

BL

SP

EQUIPMENT/ FACILITY REFERENCE LINES. SEE TABLE 2

D

BL BL

SP

d 1

3 m (API 2510) EDGE OF CATCHMENT

AREA


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REV: D2

Example 7 Group of fixed roof refrigerated atmospheric storage tanks containing

LNG (Class O product) - Double Containment Tanks

Single Containment Tanks shall have a bunded [impounding] area. Minimum distance

from tank to bund not to be less than: height of liquid level +LP gas pressure bund

height (See NFPA 59A).

Spacing

A = Minimum distance to give a max. thermal radiation flux = 32 kW/m2 in the

event of fire (approximately equivalent to 30m).

D See Table 2

A

D

d 1 d 2

EQUIPMENT/FACILITY REFERENCE LINE. SEE TABLE2


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REV: D2

Table 2 Minimum Tankage Spacing (Dimensions in Metres) (see tankage spacing

examples 1,2,3,4,5,6 &7)

Dimension C is a dimension from facility/equipment reference line to inside top of

tank bund.

Dimension D is a dimension from facility/equipment reference line to tank shell.

Examples 5,6 &7: Refer to the listed Standards for more detailed spacing requirements

regarding spillage catchment (impounding) areas and drainage. Spacing will need to be

considered for individual cases.

EXAMPLES

1,2,3,4

EXAMPLE

5 (note d)

EXAMPLE

6 (note e)

EXAMPLE

7 (note f)

FACILITY/EQUIPMENT C D C D C D C D

BOUNDARY FENCE 15 30 30 90 NA 90 NA 100

EQUIPMENT LINE PROCESS

AREA

15 30 30 50 NA 50 NA 50

BUILDINGS 15 30 30 60 NA 60 NA 60

FIXED SOURCE OF IGNITION 15 30 30 60 NA 60 NA 60

HAZARDOUS FACILITIES

(e.g. Jetty, Loading)

15 30 30 90 NA 90 NA 100

PUMP AREAS a 15 30 50 NA 50 NA 50

TANK SHELL (adjacent group) 15 30 30 50 h NA 50 NA 50 hREFRIG. FIXED ROOF TANKS 15 50 d 30 NA 30 NA 30

PRESSURE STORAGE LPG b 15 NA c 30 NA 25 NA 30

EDGE OF SITE ROADS 15 30 30 60 NA 60 NA 60

CRITICAL AREAS 15 30 30 90 NA 90 NA 100

Notes:

a To suit maintenance and operation requirements

b Assumed fitted with water deluge system.

c See notes on example 6

d, e & f: The equipment spacing listed for pressure or refrigerated storage of LPG

and the refrigerated storage of LNG, within this standard, is for initial layout purposes

(see also notes for examples 5, 6 &7). The detail design spacing will be a function of

the allowable thermal radiation flux values (permitted for fire protection) and a

hazardous assessment review. A summary of values and typical distances (in

brackets), based on a 10m height above grade from liquid product containment, is as

follows:


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d Typical maximum thermal radiation flux values* for refrigerated storage of LPG are:

The outer surfaces of adjacent refrigerated storage vessels or surfaces thermallyprotected. =32 kW/m2 (30m)

Outer surface of adjacent storage thermally protected tanks containing

flammable products =32 kW/m2 (30m)

Unprotected metal surfaces of adjacent storage tanks, pressure vessels and

process facilities = 8 kW/m2

(50m)

Protected work area, filling/discharge points = 8 kW/m2 (50m)

Urban areas, work area = 5 kW/m2 (60m)

Critical areas = 1.5 kW/m2 (90 m)

(* Reference IP LPG Vol1. Model Code of Safe Practice, Part 9)

e. Typical maximum thermal radiation flux values for pressure stored LPG are:

The outer surfaces of adjacent pressure storage vessels or surfaces thermally

protected. =44 kW/m2 (25m)

Outer surface of adjacent storage thermally protected tanks containing flammable

products =32 kW/m2 (30m)


process facilities = 8 kW/m2

(50m)

Protected work area, filling/discharge points = 8 kW/m

2

(50m) Urban areas = 5 kW/m2 (60m)

Critical areas = 1.5 kW/m2 (90m)

( Reference IP LPG Vol1. Model Code of Safe Practice, Part 9)

f Typical maximum thermal radiation flux values for LNG storage are:

Concrete outer surface of adjacent storage tanks or surfaces behind thermal

protection =32 kW/m2 (30m)


process facilities =15 kW/m2

(45m)

Control rooms, workshops, laboratories and warehouses = 8 kW/m2 (50m)

Administration building, work area = 5 kW/m2 (60m)

Urban areas = 3 kW/m2 (66m)

Critical areas = 1.5 kW/m2 (100m)

( Reference EN 1473:1997 for LNG storage- distances based upon IP LPG Vol1.

Model Code of Safe Practice, Part 9)

h Where multiple groups are required, each group shall be separated from

unprotected adjacent groups by a minimum horizontal shell-to-shell distance of 50

metres for heights up to 10m (increase to 60m for unprotecteditems above 10m).


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General:

Where space is limited in tank layout areas, the use of firewalls, thermal protectionscreens, etc. may be considered.

Special spacing is required between the listed items and oxygen and/or gaseous

hydrogen storage. Refer to the relevant standard or guide.

Documents

Piping Group & Equipment Space