pnc00003

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


– 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.



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



� 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.



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.



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.



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.



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.



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.



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



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


Recommended Equipment Spacing Charts


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

pnc00003

Documents

prevailing wind direction

lube oil consoles

main operating levels

vapor cloud explosions

process industry practices

offsites layout guide

petroleum facilities classified

check local regulations