pnc00003
TRANSCRIPT
December 1998
Process Industry PracticesPiping
PIP PNC00003Process Unit and Offsites Layout Guide
PURPOSE AND USE OF PROCESS INDUSTRY PRACTICES
In an effort to minimize the cost of process industry facilities, this Practice hasbeen prepared from the technical requirements in the existing standards of majorindustrial users, contractors, or standards organizations. By harmonizing thesetechnical requirements into a single set of Practices, administrative, application, andengineering costs to both the purchaser and the manufacturer should be reduced. Whilethis Practice is expected to incorporate the majority of requirements of most users,individual applications may involve requirements that will be appended to and takeprecedence over this Practice. Determinations concerning fitness for purpose andparticular matters or application of the Practice to particular project or engineeringsituations should not be made solely on information contained in these materials. Theuse of trade names from time to time should not be viewed as an expression ofpreference but rather recognized as normal usage in the trade. Other brands having thesame specifications are equally correct and may be substituted for those named. Allpractices or guidelines are intended to be consistent with applicable laws andregulations including OSHA requirements. To the extent these practices or guidelinesshould conflict with OSHA or other applicable laws or regulations, such laws orregulations must be followed. Consult an appropriate professional before applying oracting on any material contained in or suggested by the Practice.
© Process Industry Practices (PIP), Construction Industry Institute, The University ofTexas at Austin, 3208 Red River Street, Suite 300, Austin, Texas 78705. PIPmember companies may copy this practice for their internal use.
Not printed with State funds.
December 1998
Process Industry Practices Page 1 of 11
Process Industry PracticesPiping
PIP PNC00003Process Unit and Offsites Layout Guide
Table of Contents
1. Introduction..............................21.1 Purpose .........................................21.2 Scope.............................................2
2. References ...............................22.1 Process Industry Practices (PIP)...22.2 Industry Codes and Standards ......2
3. Definitions ................................3
4. General Requirements ............3
5. Accessways, Platforms,Ladders.....................................5
6. Roads and Paving....................6
7. Piping........................................6
8. Buildings ..................................7
9. Equipment and InstrumentAccess Requirements..............79.1 Fired Heaters and Furnaces ......... 79.2 Towers and Drums ....................... 79.3 Heat Exchangers .......................... 79.4 Pumps........................................... 79.5 Compressors and Auxiliaries ........ 89.6 Reactor and Dryers....................... 89.7 Instrumentation ............................. 89.8 Miscellaneous ............................... 8
10.Cooling Towers ........................8
11.Storage Tanks ..........................9
12.Notes on Overall Site Layout ..9
Tables:Table 1 - Minimum Access Provisions... 10Table 2 - Minimum Requirements.......... 11
Appendix:Recommended Equipment SpacingCharts
PIP PNC00003 December 1998Process Unit and Offsites Layout Guide
Page 2 of 11 Process Industry Practices
1. Introduction
1.1 Purpose
The purpose of this Practice is to provide guidance for those involved in the layoutof process units and offsites.
This guide shall be used for the development of plans, electronic models, andworking drawings for process units and offsites.
The intent is for this Practice to be coordinated with the overall site and offsiteslayout for geotechnical, grading, zoning, building codes, life safety, fire codes, andowner’s insurer’s requirements.
1.2 Scope
This Practice provides requirements for the layout of plot areas, equipment, piperacks, piping, platforms, roads, and other miscellaneous items.
Layout includes equipment location, access and egress for personnel safety, accessfor operations and maintenance, and provisions for operational housekeeping andconstructability.
Access and clearances for operation and maintenance on proprietary equipment orparts of proprietary equipment shall be in accordance with the equipmentmanufacturer’s standards.
This guide does not cover any requirements for owner safety and property protectionneeds such as loss prevention, vapor cloud explosions, or environmental or flare/ventstack requirements.
2. References
Applicable requirements in the latest edition (or the edition indicated) of the followingindustry standards and references shall be considered an integral part of this Practice. Shorttitles will be used herein when appropriate.
2.1 Process Industry Practices (PIP)
– PIP EVS003 - Specification for Noise Control (In Process)
– PIP PCCGN002 - General Instrument Installation Criteria (In Process)
– PIP STF05501 - Fixed Metal Ladders and Cages Details
2.2 Industry Codes and Standards
� American Petroleum Institute (API)
– API RP500 - Classification of Locations for Electrical Installations atPetroleum Facilities Classified as Class 1 Division 1 and Division 2
– API RP505 - Classification of Locations for Electrical Installations atPetroleum Facilities Classified as Class 1 Zone 0, Zone 1, and Zone 2
December 1998 PIP PNC00003Process Unit and Offsites Layout Guide
Process Industry Practices Page 3 of 11
– API RP752 - Management of Hazards Associated with Location of ProcessPlant Buildings
� National Fire Protection Agency (NFPA)
– NFPA 30 - Flammable and Combustible Liquids Code
– NFPA 70 - National Electrical Code
– NFPA 497 - Recommended Practice for Classification of FlammableLiquids, Gases or Vapors and of Hazardous (Classified) Locations forElectrical Installations in Chemical Process Areas
3. Definitions
Accessways: Travel ways that provide access to equipment or congested areas
Constructability: Optimum use of construction knowledge and experience in planning,design/engineering, procurement, and field operations to achieve overall project objectives
Main operating levels: Areas which, during plant operation, require plant personnel to becontinuously present or to be scheduled for presence at least once every shift
Offsites: Equipment grouped outside a process unit battery limits (e.g., tanks,loading/unloading facilities, cooling towers, flares, etc.)
Primary roads: Main traffic routes. These roads are subject to tanker and semi truck traffic.
Process Unit: A group of equipment performing a predetermined process operation asdefined by the enclosing battery limit lines. Battery limits are as shown on the plot plan.
Secondary roads: Roadways serving regular operating and maintenance traffic. These roadsare not subject to high traffic loads.
4. General Requirements
4.1 Prevailing weather and site conditions shall be considered in the development ofgeneral plant arrangements.
4.2 Plant equipment shall be located far enough from public areas and thoroughfares tominimize risk to or from the public. Obtain and apply applicable local zoning andbuilding regulations for specific setback, type of facilities permitted, and type ofconstruction allowed.
4.3 The Process Unit should be integrated within a common plant site such thatindependent operating and shutdown requirements for maintenance of other ProcessUnits is not affected. Facilities shall be provided for the isolation of a Process Unitwhen independent operation and shutdown is required for maintenance of thatProcess Unit.
4.4 Plant and equipment layout shall ensure that a safe means of egress is provided forpersonnel evacuation in the event of an emergency. Egress routes shall be continuous(not necessarily in a straight line), unobstructed, clearly marked, and lighted.
PIP PNC00003 December 1998Process Unit and Offsites Layout Guide
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4.5 Process lines, utility headers, power and instrumentation services shall be carried onoverhead pipe racks at elevations designated for each fluid service. North-south andeast-west piping shall be run at different elevations.
4.6 Fire and safety equipment shall be located to maximize accessibility and minimizeexposure to fires, explosions, or releases.
4.7 Equipment noise levels shall be considered during Process Unit location and layout(see PIP EVS003).
4.8 Equipment that handles flammable liquids, such as light hydrocarbons, should belocated downwind (considering prevailing wind direction) of fired heaters, boilers,and other equipment that may cause ignition.
4.9 Layout shall permit full utilization of plant mobile handling equipment forconstruction, servicing, and maintenance from roads through or adjacent to the unit.
4.10 Permanent handling equipment shall be limited to specific items that cannot beserviced manually or by plant mobile equipment.
4.11 Equipment that shares common service shall be grouped together where costeffective.
4.12 All special process requirements (e.g., gravity flow, self-draining, critical NetPositive Suction Head (NPSH), etc.) shall be addressed.
4.13 In general, electrical power distribution equipment should be located in anunclassified area and should be located to minimize the length of power distributionconductors. Consideration should be given to minimize exposure of electricalequipment to damage from heat sources and chemical and particulate contamination.Electrical equipment installation shall be in compliance with NFPA 70 and shall besuitable for the area classification established in accordance with NFPA 497, APIRP500, or API RP505, and local codes (where applicable).
4.14 If at all possible, catch basins, floor drains, and other flammable fluid spill collectionpoints should not be located under fixed ladders, stairways, low platforms, orflammable/heat-sensitive fluid storage equipment or close to egress points.
4.15 Spacing requirements shall be in accordance with the Equipment Spacing Chartslocated in the Appendix.
4.16 The following information shall be considered when preparing offsite plot plans:
� Prevailing wind direction
� True North as related to Plant North
� Location and elevation of railroads
� Location and extent of fencing
December 1998 PIP PNC00003Process Unit and Offsites Layout Guide
Process Industry Practices Page 5 of 11
� Location of gates
� Location of wells
� Existing and original grade elevations
4.17 The following items shall be considered when developing overall site plans forprocess plants:
� Emergency response requirements
� Legal boundaries
� Adjacent land usage
� Nearby public facilities
� Public roads
� Public utilities
� Local regulations (e.g., noise)
� Railroads
� Waterways
� Meteorology
� Site data (e.g., contaminated soil, seismic, wetlands, etc.)
� Topography
� Future development
5. Accessways, Platforms, Ladders
5.1 Ladders, platforms, and handrails shall be designed in accordance with applicableFederal Standards and Instructions of the Occupational Safety and HealthAdministration (OSHA) and PIP STF05501.
5.2 Stairs shall serve as the primary access and egress to main operating levels instructures, buildings, and furnaces.
5.3 Ladders should serve as the means of access to vessel platforms, air coolerwalkways, relief valves platforms, and all other areas not defined as main operatinglevels.
5.4 Accessways shall be provided where plant personnel are likely to pass through whilecarrying out routine duties.
5.5 Stairways shall have sufficient clearance to permit unobstructed passage for plantpersonnel.
5.6 Platforms serving vertical and horizontal exchangers shall not interfere with removalof the channel end or bundle.
5.7 Platforms around furnaces shall allow plant personnel unobstructed access at andaround piping manifolds, instruments, and furnace appurtenances.
PIP PNC00003 December 1998Process Unit and Offsites Layout Guide
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5.8 The distance between the edge of equipment and the pipe rack shall be set so thatthere is operator access to equipment and grade level instruments.
5.9 Stairs and ladders shall not obstruct access to instrumentation items.
5.10 Permanently installed stairs or other appropriate means of fixed access should beconsidered for electrical equipment and instrumentation not installed at grade.
6. Roads and Paving
6.1 Primary roads shall have sufficient horizontal and vertical clearance to permit theunobstructed travel of major vehicles.
6.2 Secondary roads shall permit maintenance vehicles to gain access to less accessibleequipment.
6.3 Accessways shall be provided as follows:
1. Under pipe racks as needed to permit crane access for routine maintenance andremoval of equipment
2. To reactors as needed to permit catalyst transfer vehicles to reach the area nearcatalyst unloading nozzles
3. At compressors as needed to permit vehicles such as flatbed trucks to enter adropout area and remove components via mobile equipment or permanenthandling facilities
4. Around other equipment as required by owner
6.4 Paving should extend as follows:
1. To the outside edge of the supporting column piers of such equipment asbottom oil-fired or combustible-liquid-containing furnaces and elevatedstructures supporting coke drums, etc.
2. Around catalyst-containing vessels
3. Around groups of two or more pumps located outdoors
4. Around compressors and their related servicing equipment (e.g., lube oilconsoles)
5. Around equipment in dirty service that requires frequent turnaroundmaintenance
6. Around equipment handling toxic liquid
6.5 Curbs required to retain spilled materials shall be at least 6 inches wide. Curb heightshall be specified to contain the required spill volume.
7. Piping
7.1 Where located at ground level, runs of lines shall not obstruct any maintenance,operational accessways, or emergency egress/access. Where crossing of walkways isunavoidable, the lines shall be provided with stiles.
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Process Industry Practices Page 7 of 11
7.2 Requirements for piping spacing around equipment shall be considered in the layout.
7.3 Additional insulation thickness shall be considered in the requirements for pipingspacing.
8. Buildings
Buildings shall be located in accordance with applicable zoning, building regulations, andAPI RP752. Where possible, locate buildings upwind of process and flammable storage tankareas (based on prevailing wind direction). All drainage shall be directed away frombuildings.
9. Equipment and Instrument Access Requirements
Note: See Tables 1 and 2
9.1 Fired Heaters and Furnaces
9.1.1 Space shall be provided for tube replacement.
9.1.2 Sufficient access and clearance shall be provided for removal ofsootblowers, air preheaters, burners, fans etc. and for operation of pressurerelief doors.
9.1.3 Heater stacks shall be extended or heaters shall be located so that stack gasesdo not drift into tall structures and columns where maintenance or operatingpersonnel may be present.
9.2 Towers and Drums
Sufficient drop space (free of obstructions) shall be allowed for removal oftower/drum internals and relief valves.
9.3 Heat Exchangers
9.3.1 Clearance for tube bundle removal and channel or bonnet removal shall beprovided.
9.3.2 Mobile access to air cooled exchangers for cooler removal/maintenance, fanmotor maintenance, and header box access shall be provided.
9.3.3 When possible, heat exchangers shall be located at grade and grouped.Tubular heat exchangers should not be stacked higher than 12 feet to the topunit centerline. If locating exchangers beneath other facilities cannot beavoided, the channel shall be clear of overhead obstructions for removalpurposes. Access shall also be provided for exchanger cleaning and/ordisassembly.
9.4 Pumps
9.4.1 Access to pump auxiliaries such as seal pots, starter button stations, motorconduit connections, etc. shall be provided.
PIP PNC00003 December 1998Process Unit and Offsites Layout Guide
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9.4.2 Clearances for removal of pump, drivers, pump rods, impellers, and otherparts shall be provided.
9.4.3 Access around and between pumps shall be provided.
9.4.4 Vertical pumps shall have appropriate overhead clearances for removal ofdrivers, shafts, impellers and other parts.
9.5 Compressors and Auxiliaries
9.5.1 Clearance shall be provided so that lube oil consoles, large castings, rotatingelements, and valves are readily accessible for maintenance.
9.5.2 Clearance and adequate laydown areas shall be provided for maintenanceactivity equipment such as lifts for large compressor cylinders and pistons,casing and impellers for centrifugal compressors, and rotors for largemotors.
9.5.3 All air compressor intakes shall be located to preclude intake ofcontaminants.
9.5.4 Adequate space shall be provided for personnel on compressor decks andaround compressor auxiliaries.
9.5.5 Lay down areas on compressor decks shall be provided on elevatedstructures.
9.6 Reactor and Dryers
Adequate space shall be provided for handling drums and/or tote bags at equipmentsuch as dryers, reactors, etc. that require frequent catalyst changes or raw materialcharging.
9.7 Instrumentation
For specific requirements see PIP PCCGN002.
9.8 Miscellaneous
9.8.1 Equipment and instruments for which no permanent access is provided shallbe located so that temporary access can be provided.
9.8.2 Reserved space shall be provided for routine maintenance activities such asfilter cartridge removal, catalyst handling, tray removal, relief valve removal,etc.
10. Cooling Towers
Cooling towers should be located downwind or crosswind (based on prevailing winddirection) of buildings, Process Units, and electrical substations and equipment.
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11. Storage Tanks
11.1 Tank spacing and location shall comply with NFPA 30.
11.2 Equipment such as pumps and exchangers should be located outside of diked storageareas.
12. Notes on Overall Site Layout
Any future plot needs, as required by the customer, for process and supporting equipmentshall be considered early.
PIP PNC00003 December 1998Process Unit and Offsites Layout Guide
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Table 1
Minimum Access Provisions
Minimum Access Required(see Note)
Type of Item to be Accessed
Platform - Items Located OverPlatform
� Elevated heat exchangers� Elevated control valves (all sizes)� Manholes (higher than 12 ft. above grade)� Relief valves (NPS 4 inlet and larger on vertical vessel)� Process blinds (higher than 12 ft. above grade)� Furnace soot blowers� Furnace burners (when not accessible from grade)� Furnace observation doors and sample ports (higher than
12 ft. above grade)� Elevated cleanouts
Platform - Items Located atEdge of Platform
� NPS 4 and larger gate and globe valves at vessels� Battery limit valves in elevated pipe racks� Elevated motor operated valves� Relief valves (NPS 3 inlet and smaller on vertical vessels)� Relief valves (all sizes on horizontal vessels)� Level controllers (higher than 12 ft. above grade)� Sampling devices on vessels (higher than 12 ft. above
grade)Permanent Ladder � All sizes of check valves at vessels
� NPS 3 and smaller gate and globe valves at vessels� Level controllers between 7-12 ft. above grade� Level gauges and valves� Furnace observation ports between 7-12 ft. above grade� Instruments requiring routine access� Handholes� Elevated electrical substations and equipment
Mobile Stair � All servicing between 7-12 ft. above grade except as notedin this table
No Permanent Access � Block valves in pipe racks (except at battery limit)� Elevated orifices or meter runs� Nozzles on vessels (without process blinds or valves)� Check valves not at vessels� Temperature connections in piping� Pressure connections in piping� Silencers or exhaust heads� Metal temperature measuring points on vessels� Instrument connections on furnaces
Note: Orifices or meter runs requiring certified calibration, as defined by owner, shall have a serviceplatform installed unless they are located at grade.
December 1998 PIP PNC00003Process Unit and Offsites Layout Guide
Process Industry Practices Page 11 of 11
Table 2
Minimum Requirements
Item Description DimensionRoads Clearance over primary access roads where major maintenance
vehicles are expected to pass
Clearance over electrical transmission and distribution lines
Width of primary access roads
Clearance over secondary access roads and pump access roads
Width of secondary access roads and pump access roads
18'-0"
22'-0"
20'-0"
10'-0"
10'-0"
Railroads Clearance over through-railroads (from top of rail)
Clearance over dead ends and sidings (from top of rail)
Horizontal clearance from track centerline to obstructions
Clearance under electrical lines
22'-0" (check local regulations)
16'-0" (check local regulations)
8'-6"
Check applicable regulations
AccessWalkways
Clearance height for projections over platforms, working areas,walkways
Width of stairways (unobstructed width)
Width of landings (in direction of stairways)
Width of walkways
Maximum vertical rise of one flight of stairway
Maximum horizontal distance from any point on platform to anemergency exit
Maximum length of dead-end platforms
7'-6” (6’-8” for bottom of valvehandwheels)
3'-0"
3'-0"
3'-0"
18'-0"
75'-0"
20'-0"
Ladders Maximum vertical rise of ladders in a single run
Maximum allowable slope of ladders from vertical
Minimum toe clearance from centerline of rung to obstruction
30'-0"
15 degrees
7"
Platforms Maximum variance in platform elevations without an intermediatestep
Minimum unobstructed width of platforms
Occasional obstructions ( level glass, transmitter, etc.)
Minimum width of manhole platforms on vertical vessels
Minimum platform extension beyond centerline of manhole flangeon vertical vessels
Minimum width of platform from three sides of manhole on vesseltop head platforms
Minimum width of platforms at ends of horizontal tube furnaces
1'-0"
2'-6"
1’-6”
3'-6"
2'-6"
2'-6"
3'-6"
OperationandMaintenance
Minimum clearance in front of channel end of horizontalexchanger for tube removal or cleaning
Minimum clearance around exchanger body flanges
Vertical exchangers
Tube bundle length plus 5 ft.
1'-6"
Unobstructed vertical access
December 1998 PIP PNC00003Process Unit and Offsites Layout Guide
Process Industry Practices Page 1 of 2
Appendix
Recommended Equipment Spacing Charts
Blo
wdo
wn
Fac
ilitie
s (D
rum
s, P
umps
, Sta
cks)
Fire
d B
oile
rs
Bld
g. H
igh
Occ
upan
cy (
Mor
e th
an 1
5 pe
rson
s)
Bld
g. L
ow O
ccup
ancy
(15
per
sons
or
few
er)
Bui
ldin
gs U
tility
Coo
ling
Tow
er
Ele
ctric
al O
verh
ead
Pol
e Li
nes
Ele
ctric
al M
ain
Sub
stat
ions
Ele
ctric
al C
ontr
ol a
nd D
istr
ibut
ion
Cen
ters
Fire
Sta
tions
, Fire
Pum
ps
Fla
re S
tack
s
Hig
hway
s, R
oads
& P
ublic
Are
as
Load
ing
and/
or U
nloa
ding
Rac
ks
Nat
ural
Gas
Met
erin
g S
tatio
ns (
Mai
n P
lt.)
Pip
eway
s (M
ajor
)
Pum
ps (
Fla
mm
able
)
Pum
ps (
Non
Fla
mm
able
)
Rai
lroad
s (M
ain
Line
s-R
/W)
Rai
lroad
s (S
purs
-Cen
ter
Line
)
Oil-
Wat
er S
epar
ator
s (A
PI-
CP
I)
Sew
er M
ains
(F
lam
mab
le)
Pla
nt R
oads
(E
dge)
Pro
pert
y Li
nes
(Oth
er th
an r
oads
& r
ailro
ads)
Pre
ssur
e S
tora
ge V
esse
ls, 5
00,0
00 g
al. o
r le
ss
Sph
eres
and
Sph
eroi
ds (
Ove
r 50
0,00
0 ga
l.)
Fix
ed R
oof C
rude
Oil
Tan
ks (
No
Flo
ater
)
NF
PA
Cla
ss II
I Lliq
uid
Sto
rage
Atm
osph
eric
, Low
& In
ter.
Vap
or P
ress
. Sto
rage
Pro
cess
Uni
ts
Blowdown Facilities (Drums, Pumps, Stacks) A 100 200 100 100 50 50 100 50 200 200 100 50 20 50 25 200 50 100 25 15 200 200 200 200 NFPA 200 100Fired Boilers A 200 100 A 100 50 100 25 100 100 200 100 20 50 5 100 25 200 50 15 100 200 300 200 NFPA 200 100
Bldg. High Occupancy (>15 persons)* A 20 150 100 100 50 0 50 100 200 200 100 50 0 150 40 200 50 50 100 200 300 200 NFPA A 200Bldg. Low Occupancy (<=15 persons)* A 0 100 50 25 0 50 50 100 100 20 50 0 25 A 100 25 30 25 150 200 200 NFPA 200 100Buildings Utility A 100 20 0 0 50 50 150 100 20 50 0 0 A 150 20 15 25 150 250 200 NFPA 200 50
Cooling Tower A 100 100 20 100 100 100 100 25 50 A 100 35 100 20 25 25 50 100 200 NFPA 200 50Electrical Overhead Pole Lines A A A 25 20 50 25 0 5 5 25 A 50 20 4 25 25 25 25 min. 25 min. 25 min. 10Electrical Main Substations A A 50 0 100 100 20 100 5 25 A 100 20 15 0 100 200 200 NFPA 200 100Electrical Control and Distribution Centers A A 0 50 100 0 25 5 0 A 50 20 15 A 50 100 A NFPA A 50
Fire Stations, Fire Pumps A 50 200 100 20 100 0 50 50 200 20 40 25 200 300 250 200 250 200Flare Stacks AHighways, Roads & Public Areas A 100 100 0 100 5 A A 100 10 A A 200 300 200 NFPA 200 100
Loading and/or Unloading Racks A 100 20 100 5 200 A 100 10 20 100 100 100 200 NFPA 150 200Natural Gas Metering Stations (Main Plt.) 10 10 50 10 25 25 100 10 15 25 100 100 A NFPA A 100Pipeways (Major) A 5 0 0 A 20 A 3 25 25 50 10 NFPA 10 15Pumps (Flammable) 3 3 100 15 10 10 10 100 25 25 A NFPA A A
Pumps (NonFlammable) 3 50 A 5 10 10 50 25 25 A NFPA A ARailroads (Main Lines-R/W) N/A A 100 10 10 N/A 200 200 200 NFPA 200 100Railroads (Spurs-Center Line) A 100 10 A A 100 100 A A A A
Oil-Water Separators (API-CPI) 25 10 15 100 200 200 200 100 200 200Sewer Mains (Flammable) A A 10 25 50 A A A 20Plant Roads (Edge) A A A A A A A 15Property Lines (Other than roads & railroads) N/A A 200 A A A 100
Pressure Storage Vessels, 500,000 gal. or less A A A A A 200Spheres and Spheroids (Over 500,000 gal.) A 100 100 100 200Fixed Roof Crude Oil Tanks (No Floater) A A A 200
NFPA Class III Lliquid Storage A A AAtmospheric, Low & Inter. Vapor Press. Storage A 150Process Units 50
Offsite Equipment Spacing*
This table does not account forvapor cloud explosions, customer safety and
property protection, environmental or flare
vent/stack dispersal requirements.
Numbers are in ft.A - Engineering/safety decision must be made
* includes control rooms
PIP PNC00003 December 1998Process Unit and Offsites Layout Guide
Recommended Equipment Spacing Charts
Page 2 of 2 Process Industry Practices
Blo
wdo
wn
Fac
ilitie
s (P
umps
, Dru
ms,
Sta
cks)
Com
pres
sors
Gas
(N
o Ig
nitii
on S
ourc
e)
Con
trol
Hou
ses
(For
Sin
gle
Uni
t)
Cen
tral
Con
trol
Hou
ses
( 2
or M
ore
Uni
ts)
Coo
lers
, Air
Fin
-Fan
Coo
ling
Tow
ers
Dru
ms-
Con
tain
ing
Fla
mm
able
s
Ele
ctric
al C
ontr
ol &
Dis
trib
utio
n C
trs
Ele
ctric
al S
witc
h R
acks
, Crit
ical
Exc
h'rs
Con
tain
ing
Fla
m/C
omb
Liq.
Fur
nace
s (P
roce
ss F
ired
Equ
ipm
ent)
Pip
eway
s (B
etw
een
Uni
ts)
Pip
eway
s (W
ithin
Uni
ts)
Pum
ps (
Fla
mm
able
)
Pum
ps (
Non
Fla
mm
able
)
Rea
ctor
s (I
nter
nally
Lin
ed &
Ext
erna
lly In
s.)
Sep
arat
or U
nit(
s) (
Ligh
t End
s)
Snu
ffing
Ste
am O
pera
ting
Val
ve fo
r F
urna
ces
Str
uctu
res
(Equ
ipm
ent &
Pro
cess
)
Tow
ers
(Fla
mm
able
)
Wat
er S
pray
Del
uge
Val
ves
Blowdown Facilities (Pumps, Drums, Stacks) A 50 100 100 50 50 50 50 50 50 100 20 5 50 25 50 50 50 50 50 50
Compressors Gas (No Ignitiion Source) 10 100 100 25 50 25 50 25 25 100 15 A 25 8 25 25 50 25 25 50
Control Houses (For Single Unit) A A 50 75 50 4 0 50 50 15 2 50 8 50 50 0 50 50 0
Central Control Houses (For 2 or More Units) A 100 100 100 4 4 50 100 15 15 75 8 100 75 0 50 75 0
Coolers, Air Fin-Fan A 50 8 50 15 8 50 A A 25 A 10 50 20 A 8 25
Cooling Towers A 50 50 15 50 100 25 3 50 A 50 50 50 50 50 15
Drums-Containing Flammables 5 50 15 5 25 5 3 5 3 10 20 20 3 8 25
Electrical Control & Distribution Centers 4 A 50 50 10 10 50 25 50 50 4 50 50 4
Electrical Switch Racks, Critical A 15 40 0 0 25 8 15 15 4 15 15 4
Exchangers Containing Flammable or Combustible Liquids A 50 3 3 5 3 10 25 20 3 8 15
Furnaces (Process Fired Equipment) 25 25 3 50 25 25 50 50 50 50 50
Pipeways (Between Units) A A 3 3 10 15 0 0 8 0
Pipeways (Within Units) A 0 0 5 A 0 0 5 0
Pumps (Flammable) 3 3 10 10 20 5 5 25
Pumps (NonFlammable) 3 8 3 3 3 5 3
Reactors (Internally Lined & Externally Ins.) 10 50 50 20 10 50
Separator Unit(s) (Light Ends) A 30 50 20 20
Snuffing Steam Operating Valve for Furnaces 0 15 25 0
Structures (Equipment & Process) 0 5 0
Towers (Flammable) 8 25
Water Spray Deluge Valves 0
Process Unit Equipment Spacing
This table does not account forvapor cloud explosions, customer safety and
property protection, environmental or flare
vent/stack dispersal requirements.
Numbers are in ft.A - Engineering/Safety decision must be
made