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ExxonMobil ProprietarySAFETY IN PLANT DESIGN Section Page

FIRE FIGHTING FACILITIES XV-I 1 of 21

DESIGN PRACTICES December, 2001

ExxonMobil Research and Engineering Company – Fairfax, VA

CONTENTSSection Page

SCOPE ............................................................................................................................................................4

REFERENCES.................................................................................................................................................4

DEFINITIONS ..................................................................................................................................................4

BASIC DESIGN CONSIDERATIONS..............................................................................................................5SINGLE FIRE CONCEPT........................................................................................................................5MAJOR FIRE RISKS, FIRE FIGHTING METHODS AND CONSIDERATIONS ......................................5

DESIGN PROCEDURES .................................................................................................................................5WATER FLOW RATE DETERMINATION ...............................................................................................5

Process Areas ......................................................................................................................................5Offsite Facilities - Minimum Requirements ...........................................................................................6

WATER SOURCE ...................................................................................................................................8SOURCE WATER QUALITY...................................................................................................................8PUMPS AND DRIVERS ..........................................................................................................................8FIREWATER DISTRIBUTION SYSTEM..................................................................................................9HYDRANTS.............................................................................................................................................9HOSE REELS........................................................................................................................................10FIRST-PHASE FIRE FIGHTING SYSTEMS / EQUIPMENT .................................................................10MONITORS ...........................................................................................................................................10FIXED WATER SPRAY / AND DELUGE SYSTEMS.............................................................................11SELECTION OF FIRST-PHASE FIRE FIGHTING EQUIPMENT ..........................................................12AUTOMATION / REMOTE OPERATION ..............................................................................................15SPRINKLER SYSTEMS ........................................................................................................................16FIRE MAIN CONNECTIONS TO BUILDINGS.......................................................................................16FOAM SYSTEMS..................................................................................................................................16FIRE FIGHTING EQUIPMENT TRUCK.................................................................................................17FIRE EQUIPMENT CABINETS .............................................................................................................17FIRE EXTINGUISHERS ........................................................................................................................17FIREHOUSE..........................................................................................................................................18COMMUNICATIONS .............................................................................................................................18MARINE TERMINALS ...........................................................................................................................18COOLING TOWERS .............................................................................................................................19FIRE TRAINING AREA .........................................................................................................................20GENERAL .............................................................................................................................................20

Changes shown by ➧

ExxonMobil ProprietarySection Page SAFETY IN PLANT DESIGN

XV-I 2 of 21 FIRE FIGHTING FACILITIESDecember, 2001 DESIGN PRACTICES


CONTENTS (Cont)Section Page

TABLESTable 1 Application of First Phase Fire Fighting Equipment ...................................................13Table 2 Water Spray Minimum Design Densities....................................................................14

FIGURESFigure 1 Determination of Water Spray Projected Area for Air Fin Coolers .............................14Figure 2 Determination of Water Spray Projected Area For Pumps.........................................15Figure 3 Typical Fire Training Area ..........................................................................................21

Revision Memo

12/01 Page 1 Added 5 new headings, Definitions, Source Water Quality, and First PhaseFire Fighting Systems / Equipment, Selection of First Phase Fire FightingEquipment, Automation / Remote Operation, Sprinkler Systems. Deleted"Sprinkler" from Fixed Water Spray Sprinkler and Deluge Systems. DeletedPortable Foam Columns and Trailer Mounted Fire Pump. Amended WaterCapacity Design Rates to Water Flow Rate Determination and Major FireRisks and Fire Fighting Methods to Major Fire Risks, Fire Fighting Methodsand Considerations

Page 4 Scope; Expanded to better reflect document content. References; Addedreferences to Onsite Design Practices XV-F/G/H/K, Marine Terminal DesignPractice XXXI-I, GP 14-3-1, TMEE 0073, NFPA 11, NFPA 13, NFPA 15.References. Updated titles for GP 3-2-1, 3-2-2, 3-10-1, 17-1-1. References.Deleted GP 3-2-5, 17-2-1, EE.50ER.68, EE.7TT.77. Added Definitions andincluded High Flash Tankage, Low Flash Tankage, Incipient Stage, FirstPhase Fire Fighting.

Page 5 Single Fire Concept: Amended wording. Major Fire Risks, Fire FightingMethods and Considerations. Title changed to better reflect expandedcontent. Introduced the concept of "incipient stage" and "first phase firefighting" Factors to note in designing and specifying fire fighting equipmentare listed.

Page 6 Water Flow Rate Determination. Title amended for increased accuracy.Wording simplified and rearranged into bullet items. Pontoon or DoubleDeck Floating Roof Tanks: References to resources available from mutualaid updated. Details of planning process for fighting large tank firesexpanded.

Page 7 Low-Flash Cone Roof Tanks. Subsurface foam as a primary form ofprotection explicitly prohibited. Introduced the possibility of provision as asecondary form of protection. Internal Floating Roof Tanks. Discussion onuse of subsurface foam reduced to a simple prohibition. The possibility ofwaiving fixed foam protection for tanks with a constant inert atmosphere isintroduced.

Page 8 High-Flash Tanks. Reasoning for not providing fixed foam protectionclarified. Possibility of providing facilities for introducing subsurface foamintroduced. Fire Water use by Process Operations amended.

Page 8 Water Source. Expanded to include caveats on use of natural sources andconsistency with GP 3-2-3. Source Water Quality. Introduced to bettercommunicate the concerns, particularly of corrosion and marine growth.Pumps and Drivers. Changes made for consistency with GP 3-2-3.Provisions for flow measuring devices and valving added to assist testingand maintenance, Provision for use of steam turbines eliminated due toavailability concerns. Clarified provisions for diverse power supplies aremaintained separate. Expanded requirement for auto and remote-manualstart. Changed reference to fire pumps to firewater pumps.

Page 9 Firewater Distribution System. Introduced the term "residual.





CONTENTS (Cont)Page 10 Firewater Distribution System. ". Amended reference to RTRP piping to

better reflect GP 3-2-3, include increased C factor. Fireproofing requirementsrelative to drainage ditches amended for consistency with GP 14-3-1.Hydrants. Expanded to reflect enhanced criteria for locating with respect toaccess. Hose Reels. Reference to 1-1/2 inch units introduced forconsistency with GP 3-2-3. First Phase Fire Fighting Systems. This conceptintroduced from EE.92E.75 as a means of better specifying when, where andhow to best use monitors and deluge systems.

Page 11 Monitors. Existing text has been rearranged to better discuss each type ofmonitor. Consideration of trailer mounted monitors as first phase equipmentis discouraged. hMobil data on wind effects introduced.

Page 12 Fixed Water Sprays. Title changed as sprinklers discussed separately.Section expanded to reflect additional heritage company data. Selection ofFirst Phase Fire Fighting Equipment. Provides a 6 step method for identifyingequipment to be protected, selecting and locating fire fighting equipment (seeTable 1), etc.

Page 14 Table 1. Guidance on the preferred form of first phase fire fighting on aprocess equipment type basis.

Page 15/16 Table 2 & Figures. Guidance on application rates and methodology fordesign of fixed water sprays

Page 16 Automation / Remote Control. A set of explicit and demanding criteriaintroduced for when automation / remote control of fire fighting systemsshould be considered.

Page 17 Sprinkler Systems. Text rearranged from former section on Fixed WaterSprays and Sprinklers. Fire Main Connections to Buildings. Caveat addedthat hose reels should only installed when an interior structural fire brigade isavailable to respond.

Page 17 Foam Systems. References to use of foam at large offsite pump stations andunattended truck loading racks added, as is need for regular testing.

General Metric measurements added throughout. "is provided" replaced with "shallbe provided" throughout.




SCOPE➧ This section covers the conceptual design of systems intended for incipient and first-phase fire fighting and to facilitate the use

of mobile equipment in a refinery or chemical plant. Also included are the basic requirements for the various equipmentcomponents of these systems

REFERENCES

DESIGN PRACTICESSection XV-F Emergency Isolation, Depressuring, and Shutdown SystemsSection XV-G Equipment SpacingSection XV-H Blast Protection and FireproofingSection XV-K Flammable Gas, Toxic Gas and Fire Detection SystemsSection XXII Storage FacilitiesSection XXXI-I Safety Considerations for the Design of Marine Terminals

GLOBAL PRACTICESGP 3-2-1 Sewer SystemsGP 3-2-2 Foam Systems for Storage TanksGP 3-2-3 Firewater SystemsGP 3-10-1 Piping Selection and Design CriteriaGP 3-10-3 Cement Lined Pipe and FittingsGP 14-3-1 FireproofingGP 17-1-1 Non-Fixed Fire Fighting Equipment

OTHER REFERENCESFire Protection and Safety Guidelines for Marine Terminals, ER&E Report No. EE.5TT.81.Emergency Preparedness for Large Tank Fires, ER&E Report No. EE.2DL.94.First Phase Fire Fighting for Refineries and Chemical Plants, ER&E Report EE.92E.75Safety Technology Manual, EMRE Manual No. TMEE 0073Standard for Low Expansion Foam, NFPA 11Standard for the Installation of Sprinkler Systems, NFPA 13,Standard for Water Fixed Sprays for Fire Protection, NFPA 15

DEFINITIONSHigh Flash Tankage - Tanks containing liquids with a closed-cup flash point of 100°F (38°C) or higher (such as heavy fuel oils,lubricating oils, transformer oils) when handled at a temperature not higher than their flash point minus 15°F (8°C).Low-Flash Tankage - Tanks containing liquid having a closed-cup flash point below 100°F (38°C) (such as gasoline, kerosene,jet fuels, etc.) and any other (high flash) stocks if handled at temperatures above, or within 15°F (8°C) below, their flash point(such as some heated asphalts). For example, a stock with a closed-cup flash point of 150°F (65°C) at a temperature of 135°F(57°C) or higher is treated as a low-flash stock.

➧ Incipient Stage - That stage of a fire immediately after ignition and before it is fully established, when persons already at thescene should be able to bring it under control and extinguish it by use of hand held fire extinguishers, wheeled extinguisher (ifimmediately available) or a fixed hose reel.

➧ First Phase Fire Fighting - The "First Phase" of a fire in process and related facilities is that period after the incipient stageand prior to the arrival, set-up and initiation of secondary fire fighting by the fire brigade and its mobile units. Operators,maintenance personnel and other field personnel carry this out using fixed fire fighting equipment. Effective fire fighting duringthis stage (typically 5 to 10 minutes) is considered crucial in limiting the degree of fire spread and overall damage.





S BASIC DESIGN CONSIDERATIONS

SINGLE FIRE CONCEPTThe extent and capacity of the fire fighting equipment provided in a refinery, chemical plant or associated facilities are based onthe assumption that only one major fire will occur at any one time. Thus, the requirements of the largest single fire contingencydetermine the design of the major fire fighting facilities. However, the sizing of the fire fighting system components may not beset by the same single fire contingency, since different fire fighting techniques are required on the various plant and offsitefacilities. For example, foam production requirements are usually determined by tank extinguishing demands, whereasfirewater capacity is usually a function of process unit requirements.

MAJOR FIRE RISKS, FIRE FIGHTING METHODS AND CONSIDERATIONSFire fighting facilities are identified in Section XV-A as one of the component classifications of a plant design directly intendedto minimize damage from fire and explosion. The other component classifications are Spacing and Layout, Fireproofing, BlastProtection, and Emergency Facilities.Process units, marine terminals, loading racks, tankage and pressurized storage facilities are typically the areas of higher firerisk.

➧ During its incipient stage some fires may be small enough to be controlled by the immediate application of a fire extinguisher orhose reel, if available. First-phase fire fighting is the effort expended by plant personnel in the early stages of a fire beyond theincipient stage, prior to the arrival of the fire brigade and the deployment of mobile equipment. Optimum control of fires andlimitation of damage can be achieved if other equipment in the fire area can be immediately protected against flameimpingement and heat radiation. First-phase fire fighting systems comprise equipment suitable for effective operator-initiatedfighting of a fire during the initial stages prior to the deployment of mobile equipment.In a process area, firewater application is the most effective fire fighting method for reducing plant damage while the source offuel is being isolated from the fire. Water is applied to exposed structures and equipment for cooling to prevent further failuresand minimize damage until the fire is extinguished, usually by shutting off or exhausting the fuel supply. In some instances(e.g., spill fires) foam can be effectively used; but this is usually of secondary importance, as far as design capacity isconcerned. The spread and impact of fire can be effectively managed by the provision of an appropriate drainage system perGP 3-2-1 and fireproofing per GP 14-3-1. Judicious use of the principles of plant layout per Section XV-G will further minimizethe impact of fire. In particular plant layout must incorporate adequate access ways for fire fightingLoading racks and marine terminals that handle flammable or combustible materials require both cooling water and foamprotection, since hydrocarbon liquid spill fires can be expected for which foam is the most effective means of extinguishment.Water is the primary mean of protection for facilities that handle LPG or similar volatile materials.Fires in tankage and pressurized storage areas are of particular concern, because of the large inventories of flammable liquids,vapors and gases involved. Foam is normally the most effective method of extinguishing a tank fire, in conjunction with watercooling of adjacent tanks. For pressurized or refrigerated LPG storage, water is the prime agent for preventing fire spread bycooling exposed facilities until the fuel supply can be isolated.In designing and specifying fire fighting equipment, three important factors must be kept in mind.• Any delay in cooling surrounding equipment increases damage and enhances the potential for the spread of fire.• Traditionally, the proper and effective use of almost all the fire fighting facilities described in this section requires the direct

involvement of personnel.• There is a continuing trend of making the most efficient and effective use of personnel available to respond to the demands

for first phase fire fighting.In specifying the provision of these systems, the analysis methodology contained in EE.92E.75 shall be followed to ensure thatfire fighting equipment and systems will be those most suitable to address the hazards present at the facility

S DESIGN PROCEDURESDesign requirements for fire fighting facilities in refineries and chemical plants are described below.

WATER FLOW RATE DETERMINATIONThe firewater system is designed to supply the water capacity requirements of the various plant and offsite areas as follows:

➧ Process Areas

The assessment of the fire water capacity requirements of a process unit is based upon a number of established considerationsand well-tested principles.




DESIGN PROCEDURES (Cont)

• Typically each process block will be split into a number of subdivisions for the purpose of establishing the maximum extentof any single fire and thus the fire water capacity requirement of that area. Each subdivision is separated from all others bya minimum of 50 ft (15 m) clear space. This spacing acts as a fire break and as a means of fire fighting access. Apipeband may be routed within a separation area providing at least 20 ft (6 m) is left clear for fire fighting access. (SeeSection XV-G for other considerations in providing fire fighting access.)

• The minimum fire water supply for any unit shall be 3000 US gpm (682 m3/h)• Experience indicates that where refinery units are laid out in accordance with Section XV-G and with a normal degree of

congestion and equipment stacking they require no more than 6000 gpm (1363 m3/h).• In older refineries, which may have more congested units in large plots and where the layout is not in accordance with

Section XV-G, the requirements can rise to 8000 gpm (1817 m3/h) or more. In such instances these large firewaterrequiements shall be provided.

• Establishing what additional potential capacity may need to be provided by means of mobile equipment such as largediameter hose and portable or mobile pumps through the local mutual aid system.

The fire water demand for each subdivision will be based upon a application rate varying between 0.1 and 0.3 gpm per ft2 [0.25and 0.75 m3/(h*m2)] of area depending on equipment density. Compact and multi-story units with a high density of stackedequipment (exchangers, drums etc.) or units containing an unusual amount of high-risk equipment (e.g. pumps handlingflammable liquid above 600°F / 316°C or above auto-ignition temperature) will require the higher rates. Similarly, considerationof the likely provision of first phase fire fighting equipment (monitors, deluge systems and hose reels) may be a useful crosscheck on capacity requirements.

Offsite Facilities - Minimum Requirements

Utility plants: 1500 gpm (341 m3)Loading racks: 1500 gpm (341 m3)Piers: 2000 gpm (454 m3/h) plus water requirement for

foam (Note 1)Large central pumping areas and similar facilities: 2000 gpm (454 m3/h)Separators and waste disposal systems: 1000 gpm (227 m3/h)Office buildings, workshops, storehouses, etc.: 1000 gpm, (227 m3/h) plus sprinkler requirements if specifiedNote 1: For the firewater requirements of Marine Terminals, see, Section XXXI-I, Safety Considerations for the design ofMarine Terminals.Tankage Areas. Water requirements for foam generation and cooling are based on the assumption of a fire on any singletank. As a minimum, 2000 gpm should be available in tankage areas.1. Pontoon or Double Deck Floating Roof Tanks - A seal fire is the design fire scenario for the purposes of determining

firewater capacity and installation of fixed equipment. A floating roof tank requires a minimum of 1500 to 2000 gpm (341 to454 m3/h) for foam generation and external cooling of its shell. For large floating roof tanks with fixed foam systems, thefoam generation requirement is determined from GP 3-2-2, and an additional 1000 gpm (227 m3/h) of water should beprovided for cooling and/or foam production for spill fire extinguishment.

➧ Although experience indicates that installation of fixed facilities to fight sunken floating roof full surface tank fires is notjustified, these fires can occur and viable emergency plans should be available to cover these contingencies. The mainthrust of these plans should be to establish the resources required and strategy for containment and extinguishment andhow they might be realistically employed through mutual aid arrangements with outside industrial and municipal firedepartments. One of the major difficulties is to supply adequate water to produce sufficient foam to obtain extinguishment.Supplemental water supplies (e.g. by use of large diameter hose and portable pumps) will need to be established withmutual aid partners, together with other support equipment and personnel. In order for these plans to achieve a "workable"status, simulated training exercises should be held regularly. Where mutual aid cannot provide the required capacity thethe facility shall give consideration to the eventuality of a full surface fire in its largest floating roof tank and develop a risk-based strategy for addressing it, including in it the possibility of increasing the amount and capacity of fixed equipment.For more details see Emergency Preparedness for Large Tank Fires, ER&E Report EE.2DL.94.Open-top tanks with pan-type floating roofs are not recommended for new construction, due to the ease of sinking the roof.However, existing pan-type floating roofs should be considered the same as cone roof tanks, with regard to fire protection.

➧ 2. Low-Flash Cone-Roof Tanks - Experience indicates that the only effective means of fighting fires within these tanks is bymeans of fixed equipment. Generally the events leading to a surface fire result in only partial removal of the roof. In suchcircumstances it is impractical to direct portable foam streams inside the tank on the fire area from any reasonably safelocation. Fixed foam systems, per GP 3-2-2 designed to handle a full surface fire is provided for such tanks.





DESIGN PROCEDURES (Cont)Subsurface foam systems should not be used as a prime form of protection. These systems are deemed unreliable asthey are inaccessible for inspection and maintenance and they require careful control and monitoring if they are to beeffective. Facilities to introduce subsurface foam protection may be provided as a secondary form of protection whenapproved by the owner's engineer and adequate mobile foam production capacity is available.Total water to be supplied to an area should be the sum of the appropriate numbers from the following three columns:

TANK DIAMETER

ft (m)

WATER FOR FOAMPRODUCTION

gpm (m3/h)per GP 3-2-2

WATER FOR COOLINGOF BURNING TANK (3)

gpm (m3/h)

WATER FOR COOLINGADJACENT TANKS(1)

gpm (m3/h)per EXPOSED TANK

Up to 20 (6) 0 750 (170) 250 (57)20 to 56 (6 to 19) 500 (114) 750 (170) 250 (57)56 to 80 (19 - 24) 500 (114) 1000 (227) 500 (114)80 to 110 (24 - 33) 1000 (227) 1250 (284) 750 (170)110 to 130 (33 to 40) 1500 (341) 1500 (341) 750 (170)130 to 140 (40 - 43) 2000 (454) 1750 (397) 1000 (227)140 to 150 (43 - 46)(max)(2)

2000 (454) 2000 (454) 1000 (227)

Notes:(1) Consider a downwind quadrant concentric with the burning tank and of radius 2D, where D is the

diameter of the burning tank. If any part of an adjacent tank is located within this quadrant, it isconsidered to require cooling. Water for this purpose should be available at a rate according to itsdiameter, as indicated in the last column.

➧ (2) Cone roof tanks (or fixed-roof tanks with internal floating covers) larger than 150 ft diameter shouldnot be used in low-flash service because of the uncertainty of being able to extinguish fires in theselarger size tanks.

➧ (3) Water for cooling the shell of a burning tank is beneficial to help in extinguishment while applyingfoam. There is questionable value in applying water to the walls of a burning tank unless asustained foam attack is planned.

3. Internal Floating Roof Tanks - The problems of fighting fires within Internal Floating Roof (IFR) tanks in Low Flashservice are similar to those noted for Cone Roof tanks in Low Flash service. Thus these tanks must be supplied with fixedequipment. Although the total fire record of fires in IFR tanks is good, approximately 50% of fires that did occur involvedsunken floating roofs. Accordingly these foam and fire water capacity requirements shall be as per Low Flash Cone RoofTanks, above. The cooling water requirements for the involved tank and adjacent tanks shall be as per Low Flash ConeRoof Tanks, above. Note that tanks in this service are restricted to a diameter of less than or equal to 150 ft (45 m).An acceptable deviation from the above is where the tank in question is an open roof tank with a pontoon-type or doubledeck design floating roof and the cover is a geodesic dome of lightweight construction. In this case, since the "roof" will failearly in any fire situation, the tank can be treated as an open top floating roof tank and the fire fighting facilities can bebased on the requirements in GP 3-2-2 for seal fires.Consideration can be given to relaxing the need for providing foam protection when an IFR tank is in a service where it isconstantly maintained under a inert atmosphere (by means of a secure supply of inert gas e.g. by nitrogen, not fuel gas),for process purposes.Subsurface foam systems shall not be used for internal floating roof tanks. Fire experience indicates that a sunken rooffurther impedes its effectiveness.

4. High-Flash Tanks - In high-flash tankage areas, experience demonstrates that the fire risk is low enough that investmentin fixed extinguishment systems is not justified. Water resources are provided to restrict the spread of fire to adjacenttanks and protect them from other exposures. The rates required are based on cooling adjacent tanks only, calculatedaccording to the final column of the above table for low-flash cone-roof tanks. When local regulatory provisions require theprovision of a fixed system for a tank in High-Flash service, a semi-fixed subsurface system, designed per NFPA 11 maybe supplied for this service, provided the tank has a fixed roof, no internal floating cover and stores non-polar liquids.

5. Pressurized and Refrigerated Storage - Firewater requirements are based on supplying the deluge system of any onevessel which is assumed to be on fire, plus the deluge systems of adjacent exposed vessels, plus 1000 gpm (227 m3/h)from monitors and hose streams for cooling surfaces not covered by the deluges, as specified in GP 3-2-3.




DESIGN PROCEDURES (Cont)Firewater Use for Process Operations - Connections must not be made into the fire main to supply regular process or utilityrequirements or for recurring line flushing or product displacement purposes. Occasional use (via hose only) for purposes suchas hydrostatic testing or water flushing of vessels is allowable provided this is done in accordance with the facility work permitsystem that includes provisions for immediaterly stopping such use of firewater in an emergency. One permissible exceptionfor continuous use is water to a flare seal, if this achieves a significant saving by eliminating a special branch of the coolingwater system.

➧ WATER SOURCEFire water supply can be drawn from a number of sources, but a large body of unlimited water such as sea water, a lake or ariver, is the preferred source. At least one alternative supply source shall be provided where the environmental conditions(tides, water plants / weeds, seasonal water fluctuations etc.) affect the availability or quality of the primary natural watersource.More than one source is required where the maximum demand for process facilities is greater than 6,000 gpm (1363 m3 /h).Where it is not possible to obtain an unlimited source, alternatives may be the use of wells or a connection to a municipal firemain, if these sources can be assured to be of suitable capacity and availability to meet the requirements.Where the water source is limited, an acceptable alternative is to provide a firewater storage system. This storage must belarge enough to provide full design flow for a minimum of 6 hours without shutting down the process or other water-usingoperations in the refinery or plant. Also, the water-source must be capable of supplying one-half the maximum water demandon a continuous basis after the storage capacity has been used. The continuous supply at one-half the maximum demand ratecan be based on taking credit for shutting down non-critical process facilities by the end of the 6-hour period, if this is feasible.

➧ SOURCE WATER QUALITYTreatment facilities shall be provided for systems having brackish or saltwater as a supply source. Provision needs to be madein the design of systems using salt or brackish water to mitigate the potential problems of corrosion and fouling with marinegrowth associated with this quality of water.Water supplies shall not contain agents that could affect the quality of fire fighting foam production. The water supply must beoil-free and must not be obtained from skim ponds, ballast water tanks, etc., as slight traces of oil act as a defoaming agent.Process cooling water or other process water streams shall not be used if emulsion-breaking or anti-foam compounds are usedin the water treatment process.

PUMPS AND DRIVERS➧ The firewater pumps must have a total rated capacity at least equal to the largest single demand. Pumps with additional

capacity may be more economical in order to obtain commercially available units. Normally pumps with a rated capacity nogreater than 3000 gpm (682 m3 / h) should be specified.

➧ Total pump capacity requirements shall be provided in the form of at least two pumps, having different types of drive. The onlyexception is for facilities with a total demand of 1500 gpm (341 m3/h) or less - see GP 3-2-3. At least one pump should beelectric motor driven and at least one pump should have a diesel engine drive. Where more than two pumps are required theyshould be of equal capacity and an appropriate selection of drivers should be specified to give maximum reliability. Where twoelectric driven pumps are to be utilized, they shall be fed from separate power supplies, that shall be arranged such that thefailure of one supply will not cause an interruption of the other source.

➧ While there is no requirement for sparing fire water pumps, this is based on the assumption that these shall be given thehighest priority for maintenance and that there is a proven, reasonable expectation that repairs can be completed in 24 hours oralternative pumps can be obtained in that time. Where such assumptions may not be valid, consideration should be given toinstalling at least one spare firewater pump.The firewater main shall be designed to operate continuously at 125 psig (860 kPag) at the pump discharge manifold. Anadjustable set point pressure controller shall bypass excess flow from the pump discharge back to the source of supply.Firewater main pressure should not exceed 165 psig (1138 kPag) (use of balanced foam proportioning equipment above 165psig (1138 kPag) can result in ineffective foam generation).A return line with a flow-measuring device shall be provided for periodic testing of firewater pumps. The flow-measuring deviceshall be sized for at least 175 percent flow of the largest firewater pump. Isolation valves shall be provided to permit isolationand maintenance of an individual pump while the other pumps remain in service.A small pressurizing pump (commonly called a jockey pump) manifolded in parallel with the main firewater pumps, pressurizesthe system when the latter are not in use. Rated capacity is normally 300 to 500 gpm (68 m3/h to 114 m3/h) at 125 psig (860kPag). This quantity is not included in the total firewater pump capacity.





DESIGN PROCEDURES (Cont)➧ A low-pressure cut-in with alarm shall be installed on the pump discharge manifold, set at 100 psig (690 kPag), to actuate an

automatic starting device on the electric motor driven firewater pump. Remote start control of this pump is also provided at acontinuously attended control room or at the firehouse. Where more than two firewater pumps are provided further pressuredrop shall automatically start secondary fire water pumps to meet at least 50% of the total required pumping capacity, with a5 - 10 second timed delay. The remaining diesel or electric driven firewater pumps may be manually started from a constantlyattended location or can be automatically started as the firewater demand continues to increase. As a backup to the mainfirewater pumps, multiple hose connections should be installed at the Marine Terminal at two separate berths so that fireboatsor tankers can pump into the refinery main.As a backup to the pressurizing pump, a cross connection to the cooling water system may be provided, fitted with block andcheck valves, and sized to pass 300 to 500 gpm gpm (68 m3/h to 114 m3/h). Further design details of firewater pumps anddrivers are specified in GP 3-2-3. Firewater pumps must be located in areas not subject to fire exposure. Therefore, aminimum of 150 ft (45 m) spacing to most types of operating equipment containing hydrocarbons is specified, in accordancewith Section XV-G.

FIREWATER DISTRIBUTION SYSTEM➧ A grid or looped piping distribution system shall be used, capable of supplying water, on a single fire basis, to any part of the

refinery at the design rate determined for that specific area. The design is based on water flow through all loops and mains ofthe grid system, and the lines are sized to provide 80 psig (552 kPag) minimum hydrant (residual) pressure at full design flowrate. Piping should be sized conservatively to account for fouling and increased roughness caused by aging. Firewaternetworks are typically designed using the Hardy Cross method of analysis. PC based software is available to optimize pipesizes in order to obtain a reliable and economic design. In the absence of other programs, the following combination of theHardy-Cross, and Hazen and Williams methods may be used for sizing the pipe:

Q = 0.0368 c d2.63 p0.54

where: Q = Flow rate, gpmc = Hazen-Williams Coefficient, dimensionless - see belowd = Inside diameter, in.p = Pressure drop, psi per 100 ft of pipe

➧ The Hazen-Williams coefficient, c, is a type of roughness factor. It is recommended that a value of c = 100 be used, exceptwhere reinforced plastic (RTRP Grades) or FiberglassTM Reinforced Plastic (FRP), per GP 3-2-3, are to be used and a value ofC = 120 is more appropriate. Generally the minimum sizing will be NPS 8 for fire water mains and NPS 6 laterals.The fire main grid shall be designed with isolation valves, which permit sections to be taken out of service for repair while stillretaining half the design capacity to each area. GP 3-2-3 specifies details of the grid design, which ensures that this reducedcapacity is distributed such that adequate equipment coverage is maintained.

➧ Refer to Construction Materials Manual II-L for materials and lining requirements for firewater piping. Use of reinforced plastic(RTRP Grades) or Fiberglass Reinforced Plastic (FRP) piping has been used at some locations for underground systemsbased on site-specific economics.Fire mains shall be fireproofed at any location where they cross drainage ditches into which liquid hydrocarbons may bedischarged. Elevated supports located 20 ft (6 m) or less beyond the edge of the drainage ditch shall be fireproofed. Furtherdetailed requirements for fire main piping and valving are defined in GP 3-2-3, GP 3-10-1, and GP 3-10-3.

➧ HYDRANTSA sufficient number of hydrants must be provided to supply the required water rate in each area. A normal flow of 750 gpm(170 m3/h) can be assumed from each hydrant when using three 2-1/2 in. (63 mm) hose lines. This increases to 1000 to 1200gpm (227 to 272 m3/h) when a pumper is connected to take suction from a hydrant.Hydrants should be located within 250 ft (75 m) of any point where water will be required. Maximum spacing between hydrantsshall be 150 ft (45 m) in onsite areas and 300 ft (90 m) in offsite areas containing equipment. The locations should be arrangedto permit equipment to be reached from at least two opposite directions, so that manual hose line approaches can be madefrom the upwind side. Where appropriate, hydrants shall be positioned so that they may also be used to protect equipment inadjacent units or areas. Further detail spacing and location requirements are covered in GP 3-2-3, which also covers details ofhydrant design, connections, etc.Hydrant connections should be compatible with local community and mutual aid mobile fire fighting equipment that may beused in a major incident.





HOSE REELSHose reels fitted with 100 ft (30 m) of 1-1/4 in. (32 mm) or 1-1/2 in. (38 mm) firm type hose and combination straightstream / fog nozzles are provided in all operating areas as a means of quickly applying water to fires in the incipient stage.They should be located in onsite and some offsite areas to provide coverage for equipment which is likely to be a source ofhydrocarbon release, i.e., major pump areas, loading racks, pier manifolds, etc. In process and utility areas, complete groundlevel coverage is necessary except for equipment handling non-flammable or low-risk materials. While overlapping coverageby adjacent hose reels is not necessary (generally they will be located on 200 ft (60 m) center spacing), they should be locatedsuch that one is accessible from each side of a unit. The minimum number of hose reels in a process unit shall be two, locatedat opposite sides of the unit. Hose reels, supplied from a fire main riser, should also be provided at all main platforms of majorelevated structures such as catalytic cracking units.Detailed hose and hose reel equipment are defined in GP 3-2-3.

➧ FIRST-PHASE FIRE FIGHTING SYSTEMS / EQUIPMENTUpon discovery of a fire within a unit, operating personnel are immediately faced with a number of vital tasks that must beaddressed simultaneously, including ensuring safety of personnel, isolating affected equipment and/or shutting down the unit,and fighting the fire. This latter task is referred to as first-phase fire fighting. To maximize the benefit that first-phase firefighting offers to a facility it should both provide an effective response until the fire brigade arrive and are properly deployed,and minimize the time required of operating personnel to activate or supervise it.While the implications of the above are discussed in ER&E Report No. EE.92E.75, first phase fire fighting equipment must meetthe following criteria:1. The equipment must permit quick and easy initiation of operation.2. The equipment must require only intermittent attendance.3. The equipment must be highly effective.4. The equipment must be positioned to cover the most critical parts of the protected area.5. The equipment must not be complicated (i.e. it must not have a high maintenance requirement and must have a high

availability).In practical terms there are only two types of equipment that are capable of meeting the above criteria; firewater monitors andfixed firewater spray systems. The merits and drawbacks of this equipment are discussed below:Critical Parts of the Area - In assessing the criticality of equipment in a unit or process area thought has to be given to theconsequences of that equipment being unprotected and exposed to a sustained fire, both in direct terms (i.e. the loss of thatpiece of equipment) and indirectly in terms of potential spread of the fire upon failure, and extended production downtimes.Examples of equipment considered critical in this context:• Vessels with large inventories of flammable materials, particularly those with unwetted internal surfaces. Examples include

large vapor filled reactors and internally insulated vessels, as they are potentially subject to early failure due to the lack ofany cooling effect from contained liquids.

• Equipment containing flammable materials that may be released due to failure of components such as gaskets or pumpseals exposed to radiant heat or direct flame impingement. Two classes of material of particular concern upon release arethose being processed above their auto-ignition temperature and flammable liquids such as light ends which may formvapor clouds that could explode if subject to a delayed ignition.

• High value equipment. This may be equipment with a high intrinsic cost such as large centrifugal compressors. It mayalso be equipment which is designated as critical by virtue of its importance to the continued operation of a particular uniteither because the unit is vital and any down time has a large cost impact or the loss would result in a protracteddowntime.

MONITORS➧ Monitors with combination straight stream / fog nozzles are provided as the means of applying large volumes of cooling water

onto process equipment and facilities. They may be operated very effectively and require very little training or physical effort.Monitors shall be capable of delivering not less than 500 gpm (114 m3/h) and shall have an assumed effective straight streamnozzle range of 100 - 120 ft (30 - 36 m) at 80 psig (550 kPag) residual pressure in still air. The influence of cross or opposingwinds should be recognized as, typically a 5 mph opposing wind can reduce the effective range as much as 50%. Generally allmonitors are left in a preset fog pattern to obtain maximum cooling when they are operated. Fog streams are effective at muchshorter distances, e.g. 60 ft (18 m) maximum range with a 30 degree cone setting.

➧ Monitors used in refineries, chemical plants and associated facilities are classified as fixed, elevated and trailer-mounted.





DESIGN PROCEDURES (Cont)➧ Fixed (ground level) monitors are located a minimum of 50 ft (15 m) spacing from the equipment being protected in order to

allow access during fires. These units have the advantage that a single monitor operated by a single operator can, whenstrategically positioned, provide coverage for all equipment within its range. Where monitors have to be located less than 50 ft(15 m) from equipment in order to provide coverage, the monitor's operating valves should be remotely located at 50 ft (15 m)so as to be accessible during a fire. In this situation each monitor would be set to concentrate its water flow on a particular setof equipment, and more monitors may have to be added to ensure overall coverage of critical equipment. Consequently theseare less efficient users of fire water.

➧ Elevated monitors, remotely operable from grade, are appropriate where coverage of a close grouping of elevatedequipment (such as drums, exchangers and towers) is required or where obstructions exist near grade that would preventadequate coverage of critical equipment by manually attended fixed monitors at grade. Typically these units would be activatedby means of a grade level valve and would be set to concentrate their water flow on a particular set of equipment, as theadvantage of operator attendance / control is lost. Elevated monitors may be provided with remote controls, such that they canbe directed to protect various pieces of equipment, but this approach should be considered only in situations where use ofmobile equipment is not feasible. An example would be on finger piers to provide protection to both the pier and berthedvessels. The complexity of these controls and the relatively high maintenance demand render such units generallyunacceptable for first phase fire fighting in most refinery and chemical plant applications.Trailer-mounted monitors can be used where effective coverage is difficult to achieve due to obstruction by pipe bands andequipment. Trailer mounted units should be located adjacent to access ways to facilitate maneuverability during a fire. Eachunit is normally stationed at a hydrant or pipe outlet and connected to it with 100 ft (30 m) of 2-1/2 in. (63 mm) hose. Trailermounted monitors have the advantage of flexibility, since they can be moved into position for maximum effectiveness, but thisadvantage is at the expense of a time delay in the application of firewater and increased demands on operating personnel.Because of these limitations, trailer mounted units are not generally the first choice for providing first phase fire fighting.

FIXED WATER SPRAY / AND DELUGE SYSTEMS➧ Fixed water spray / deluge systems may be utilized as first phase fire fighting equipment for either exposure cooling of vessels

and equipment likely to be exposed to fire or fire intensity control on equipment that may be a source of fire (typically pumpsand compressors in flammable service). In process areas open head dry-pipe systems, manually activated by a valve locateda minimum of 50 ft (15 m) from the equipment being protected and easily accessible to operators, are used. These systemsshall be designed in accordance with NFPA 15 (in the USA) or equivalent and GP 3-2-3. Application rates can vary from 0.15gpm per ft2 (0.37 m3/h*m2) for cooling of spheres and spheroids to 1.3 gpm per ft2 (3.1 m3/h*m2) for the internal firewater spraysystem for regenerative air preheaters (see Step 6 of the selection procedure and Table 2, below). The use of individual fixedwater spray systems having a total capacity in excess of 2000 gpm (454 m3/h) is generally not recommended as they can resultin poor efficiency of water usage.

➧ Spray heads may be upright type or pendant type, depending on local preference and shall have a minimum orifice opening of3/8 in. (10 mm) to minimize the risk of plugging as specified in GP 3-2-3. Mushroom type deluge heads for the top systems forpressurized and refrigerated storage spheres and spheroids shall be per GP 3-2-3. Fixed water spray system pipingdownstream of the system strainers shall be copper-nickel or galvanized.

➧ While fixed water spray / deluge systems can provide excellent fire protection and are more efficient than monitors in providingprotection of specific pieces of equipment, there are significant disadvantages with the use of these systems.1. They can be prone to internal corrosion and plugging.2. Regular testing is necessary to ensure system availability. Testing may involve deluging operating equipment with water

which may initiate flange leaks on hot equipment and could (depending on the quality of the fire water) accelerate externalcorrosion of the equipment. To avoid these problems temporary shielding of the equipment may be required, which makestesting more difficult.

3. Due to their proximity to the equipment being protected, they may be incapacitated at the onset of a fire either because anexplosion precedes the fire or the piping is subjected to flame impingement prior to water flow being initiated.

4. Inspection is required to verify that flow patterns are not rendered ineffective when equipment supports are moved,equipment added or after equipment has been maintained or by mechanical damage.

Despite the above caveats it is possible to provide operable systems capable of many years of reliable service by acombination of sound design, robust construction and an commitment by the client organization to an ongoing and rigoroustesting and maintenance program.





➧ SELECTION OF FIRST-PHASE FIRE FIGHTING EQUIPMENTBased upon the criteria given above for determining equipment as suitable for first phase fire fighting and upon experiencewithin ExxonMobil facilities the preferred order for selecting equipment is as follows:1. Fixed monitors capable of local manual operation and control2. Fixed or elevated monitors capable of remote manual operation.3. Fixed water spray / deluge systems capable of remote manual operation4. Trailer mounted monitors.5. Elevated monitors capable of remote manual operation and remote manual manipulative control.Note: Items 4 and 5 are only considered "first phase" equipment under special circumstances - see text above.Table 1 discusses the coverage requirements of equipment that may be considered critical. It will be noted that in specificcircumstances the preferred method of application may differ from the general ranking given above.The procedure to follow in selecting first phase fire fighting equipment is as follows:1. Determine the equipment to be designated as critical per the criteria given in Critical Parts of the Area, above.2. Review Table 1 for the preferred form of coverage for the identified critical equipment.3. Fixed monitors to be located around the perimeter of the unit and should be positioned to achieve the maximum coverage

of critical equipment and facilitate operator access.4. Where Table 1 indicates alternate forms of coverage, provide accordingly.5. Provide appropriate protection for equipment not provided with coverage per steps (3) or (4) In making that selection

consideration needs to be given to the following:• Availability of personnel• Realistic response times• Operator access• Prevailing winds• The quality of firewater (fresh, salt, brackish etc.)• Commitment and capability of client organization to necessary testing and maintenance• Availability and capability of fire brigade to provide a secondary fire fighting response• Adherence of layout and spacing to requirements of Section XV-G (see Table 1)• Provisions for unit/equipment shutdown/isolation/depressuring and relevant emergency response philosophy (see

Table 1, Note 1).6. Where fixed water sprays are used, either as the preferred option or where monitor use is not viable, guidance on the

firewater application rate to be used in designing systems for protecting specific equipment is to be found in Table 2.Where no guidance is given, rates should be no less than 0.2 gpm per ft2 (0.48 m3/h*m2) or as per NFPA 15, whichever isgreater.





➧ TABLE 1APPLICATION OF FIRST PHASE FIRE FIGHTING EQUIPMENT

TYPE OF CRITICALEQUIPMENT OR UNIT

APPLICATION OF FIRST PHASE FIRE FIGHTING EQUIPMENT(FIXED MONITORS PREFERRED, UNLESS OTHERWISE STATED)

Process Unit Towers For externally insulated column-type vessels, their reboilers and their hot oil piping and bottomconnections

Process Unit Pumps andCompressors

Ensure coverage of motors and seal areas plus lube oil console for compressors

Heat Exchanger Banks For channel sections (or expansion joints) and flanged connections

Process Unit Heaters Only for exposed return bends and crossovers(1).

Process Unit Air Coolers When they contain volatile liquids (light ends) at pressures over 250 psig (170 kPag) or materialsabove their auto-ignition temperature.

Offsite Pumps For larger or higher-risk offsite pump stations (see also "Foam Systems", below).

Partially Confined Areas Typically compressor units or multi-story reactors provided with one or more walls, floors etc.Provision of monitor nozzles or elevated monitors in a preset position is preferred. Where fullcoverage is still not possible, use fixed water spray.

Lube Oil Refineries For chillers, filters, and similar equipment in solvent extraction process.

Cooling Towers For those constructed of combustible material provide coverage for all sides and top deck

Pressurized (horizontal) StorageVessels

Coverage of areas containing nozzles or valves etc., per GP 3-2-3.Entire coverage of single or two vessels within 50 ft (15m) of each other, per GP 3-2-3, when notfireproofed.

Ammonia Tanks Deluge system for entire vessel(2).

Pumps and Compressors inCongested Areas

Particular attention to be paid to equipment handling fluids above auto-ignition temperature, lightends, or other flammable liquids at pressures above 500 psig (345 kPag) with the potential tocause vapor clouds upon release. Fixed water spray systems designed for fire intensity control /vapor dispersion may be most appropriate (see Table 2).

Spheres and Spheroids inPressurized and RefrigeratedStorage Service

The upper hemisphere shall be provided with a top mounted, mushroom head type deluge systemper GP 3-2-3. Monitors or fixed sprays shall be provided for the lower hemisphere per GP 3-2-3.

Dome Roof Tanks in RefrigeratedStorage Service

A top mounted mushroom head type deluge system per GP 3-2-3 shall be provided. In addition,spray rings will be provided where required by GP 3-2-3.

Regenerative (Rotary) AirPreheaters

A fixed internal spray system shall be provided per GP 3-2-3.

Spot Loading Rail Tank Cars Coverage of loading facilities where a centralized loading point is provided.

Tank Truck Loading Racks Coverage is required for refinery and other major racks (3). Fixed monitors are sufficient forconstantly attended racks. For non-attended racks see "Foam Systems" and “Automation".

Multilayer Pipe Racks inCongested Areas

Where multilayer pipe racks are surrounded by congested process equipment and there is thepossibility of any spillage from damaged piping to accumulate under the rack, then elevatedmonitors shall be provided (4).

Notes:(1) Monitor coverage is not normally required for process heaters as exposure to fire is not likely to result in immediate damage or

loss of containment. The primary vulnerability of heaters to damage relates to split tubes. Where this could result in significantspillage and drainage capability is limited then monitor coverage may be justified as a means of washing the spill away from thevicinity of the process heater to a less hazardous location.

(2) Only required when located within 50 ft (15 m) of potential external hydrocarbon fire.(3) See ER&E Report No. EE.92E.75 for assistance in designating racks as "major".(4) This should not be the situation in grass roots plants where layout and spacing is in accordance with Section XV-G and the

sewer system is designed per GP 3-2-1.Other applications - There may be other situations where specific conditions call for the use of first phase fire fightingequipment. Section XV-G permits provision of dedicated fixed water spray systems for pumps handling flammable orcombustible materials as a justification for reducing their spacing from onsite pipeband. When working in existing facilities,provision of fixed water spray may be provided on equipment where spacing and separation does not comply with the currentrequirements of Section XV-G. Where cylinders containing hazardous chemicals are installed and located in the vicinity of aprocess area per Section XV-G, or other potential fire risk areas, fixed water sprays should be considered.





➧ TABLE 2WATER SPRAY MINIMUM DESIGN DENSITIES(1),

[For use in designing Fixed Water Spray Systems]

EQUIPMENTPROJECTEDAREA BASIS

gpm/ft2 (m3/(h*m2)

FOR ACTUALSURFACE AREAgpm/ft2 (m3/(h*m2)

Air Cooled Exchangers(2) 0.25 (0.6) (3) NASphere / Spheroid NA 0.15 (0.37)Pumps, Compressors, Turbines, and Motors(1) 0.6 (1.5) (4) NADome Roof Tanks - Top NA 0.15 (0.37)Dome Roof - Side NA 0.15 (0.37)

Vessels/Exchangers(1) NA 0.25 (0.6)Fired Heaters - Exposed Bends(1) NA 0.25 (0.6)Regenerative (Rotary) Air Preheater (Vertical) NA 1.3 (3.1)(5)

Regenerative (Rotary) Air Preheater (Horizontal) NA 1.3 (3.1)(6)

Notes:(1) Where spacing is less than required per Section XV-G, or in areas of higher congestion, increased water spray

rates must be used.(2) Monitors are preferred protection for this equipment - see Table 1.(3) See Figure 1.(4) Projected area extends 2 ft (0.6 m) in all directions from pump - see Figure 2.(5) Upper face only.(6) Both faces

The location of first phase fire fighting equipment should normally be finalized only after consultation with EMRE Safety andRisk Section and the site fire marshal. Further details are given in GP 3-2-3 and in EMRE Report EE.92E.75

FIGURE 1DETERMINATION OF WATER SPRAY PROJECTED AREA FOR AIR FIN COOLERS

Fin Tubes

DP15If01

Projected area (of fin tubes) for calculation of required water spray densities at0.25 gpm/ft2 (0.6 m3/hr-m2)

Direct sprays on underside. If forced draft, install nozzles in plenum betweenfan and fin tubes.






FIGURE 2DETERMINATION OF WATER SPRAY PROJECTED AREA FOR PUMPS

Pump

ProjectedArea

Minimum Design Area4 x 6 ft (1.2 x 1.8m)

Driver

ProjectedArea

2 ft (0.6m) Min.

2ft (0.6m ) RadiusBeyond Pump Case

DP15If02

A. Canned or In-line Pump(Plan view)

B. Horizontal Pump with Driver(Plan View)

2 ft (0.6m) Min.

Pump

➧ AUTOMATION / REMOTE OPERATIONInitiating the appropriate isolation / shutdown / depressuring, calling for additional fire fighting resources, and bringing thenecessary first phase fire fighting equipment into operation are the single most effective actions for containing any fire andminimizing its impact. In modern facilities many of these actions can be achieved remotely from the control room or from thebattery limit valves manifold (or manifolds), per Section XV-F. The approach to first phase fire fighting equipment may besummarized as being to keep it simple, robust, and distributed, with reliance on operator manual / local action. Experience hasdemonstrated the validity of this approach as this equipment has proven to be highly reliable and available, sometimes withonly the minimum of basic maintenance. The key to this effectiveness of response has been the availability and presence ofoperating personnel. With the trend for reducing the field presence of operators, the assumption that there will always be thenecessary personnel available to respond within the vital first few minutes may not always be valid.




DESIGN PROCEDURES (Cont)Where the client organization does not have the resources to guarantee the type of response required for the effective use of atraditional first-phase fire fighting equipment additional means of maximizing the utilization of available resources must beconsidered. This could be as simple as manifolding the operating valves for all deluge systems for each side of a unit to asingle location closest to the Control House, or it could involve use of automatically activated fire fighting systems.Enhancements to first-phase fire fighting equipment will generally result not only in increased capital cost, but also higheroperating costs due to the need for more frequent testing and maintenance. These cost increases need to be balanced againstthe cost savings that accrue from reduced operating manpower.The use of automated systems for first-phase fire fighting in outdoors process facilities has not been commonly made becauseof the following concerns:• Increased Cost, both capital and expense(see above).• Increased Resources, in terms of number and capability of personnel necessary to meet the higher testing and

maintenance demands.• Lower Availability, the more complex a system is, the higher the potential for unrevealed failures and thus for the system

not to be available to operate on demand.• Lower Reliability, the more complex a system is the higher the potential for spurious activation that can disrupt operation

and create potential safety hazards.Despite these legitimate concerns, automatically activated fire fighting systems are frequently used within certain Downstreamoperations, such as unattended truck loading racks. Section XV-K includes examples of deluge systems activated by acompressed air/pilot head system that operates satisfactorily. Automatically activated systems using pilot heads and otherforms of detection as initiators are also used extensively in Upstream facilities such as offshore platforms.When considering the use of automatically activated first phase fire fighting equipment the caveats contained in Section XV-Kregarding use of fire detectors should be noted. Before committing to the use of automatically activated equipment thefollowing should be reviewed individually and in combination for their applicability to the situation at hand and an assessmentmade of the viability, effectiveness and benefits offered by automatic activation.• Degree of risk: The equipment to be protected should be higher risk either due to the fluids being handled (e.g. liquids

above their auto-ignition temperature) or location (e.g. the potential for rapid escalation and significant threat to life and orequipment). The potential for escalation is greater for facilities that do not meet the spacing requirements of Section XV-Gor the drainage requirements of GP 3-2-1).

• Availability of Personnel: The client organization cannot guarantee manual fire detection and/or an effective responsefor first phase fire fighting within the first five minutes.

• Congested Equipment: This may heighten the degree of risk associated with the equipment (see above), and/or be suchthat it severely impedes the possibility of visual detection of a fire.

• Degree of Device Complexity: The detection and initiation equipment, while appropriate for the risk being protectedagainst, should be of proven and robust design, with preference given to established "Low Technology" approaches.

➧ SPRINKLER SYSTEMSSprinkler systems designed and installed as per NFPA 13 (in the USA) or equivalent are required for high-risk indoor facilities,such as warehouse storage of butyl rubber, drummed low-flash products, bagged ammonium nitrate, or similar materials. Areputable sprinkler company should carry out detailed design.

FIRE MAIN CONNECTIONS TO BUILDINGS➧ In facilities with an interior structural fire brigade the fire main system should be extended into buildings of relatively high fire

risk, such as laboratories, workshops, warehouses, and storehouses, and hose reels should be provided. In multistory officebuildings a standpipe is the minimum requirement.For low-risk single-story buildings, e.g., offices, an outside hydrant is adequate.

FOAM SYSTEMSA foam system shall be provided for fighting storage tank fires and typical oil spill fires at tankage areas, marine terminals,loading racks and process units. A system relying on fixed discharge devices and foam proportioning from fire trucks should beused for maximum flexibility and effectiveness, with fixed application facilities in certain cases. This is generally referred to as asemi-fixed system.





DESIGN PROCEDURES (Cont)➧ A 3 vol. % foam solution in water is used, which is expanded to 6 to 8 times its volume by air aspiration, where water-miscible

liquids such as alcohol and ethers (MTBE). Such materials require a special foam compound and application technique(consult the Safety and Risk Section of EMETD for advice).In the semi-fixed system, an foam proportioning truck mixes foam concentrates into the water stream and pumps the resultingfoam solution to the foam making device. The foam maker aspirates air into the solution forming a stable foam.Foam makers are located in fixed laterals to certain specified tanks for internal application to the liquid surface, or hose lines ormonitor nozzles for application on ground spills.

➧ Fixed foam laterals are required for cone roof tanks in low-flash service, per GP 3-2-2. High back pressure type foam makersare used, located at the base of the tank, from which the expanded foam is piped to the foam chamber at the top of the tankshell.

➧ The contingency of fire on the largest low-flash cone roof tank normally sets the required generating capacity of the foamproportioning equipment. This is based on a foam solution rate of 0.1 gpm per ft2 (0.25 m3/(h*m2) of tank liquid surface fortanks up to 100 ft (30 m) diameter, and 0.11 gpm per ft2 (0.28 m3/(h*m2) for tanks over 100 ft (30 m) diameter. The foamgenerating capacity specified for the foam proportioning truck in GP 17-1-1 is sufficient, on the above basis, for a tank of up to110 ft (33 m) diameter, depending on the type of proportioning system employed. For larger tank diameters, a second foamproportioning truck must supplement capacity. For isolated locations where mutual aid is not available, sparing the foamproportioning truck should be considered.

➧ Semi-fixed foam facilities are also required for floating roof tanks in accordance with GP 3-2-2. In some cases theserequirements may determine the capacity of the foam generating equipment if there are no cone roof tanks requiring foamfacilities.

➧ Monitors providing coverage for large offsite pump stations may be provided with combination foam / water monitors and foamsolution. In locating such monitors, this resulting loss of range needs to be taken into account.

➧ Unattended truck loading racks should be provided with an automatically activated foam water spray system. Attended T/Tloading racks should be provided with a remotely operated foam-water spray system.If the installation does not include low-flash cone roof tanks or floating roof tanks with fixed foam systems, a foam proportioningtruck is still required for use with hose lines for extinguishing loading rack fires and spill fires in general.Full details of the foam proportioning truck are specified in GP 17-1-1.A foam concentrate tank truck is required to replenish the foam concentrate tanks on the foam proportioning truck. Details ofthis vehicle are specified in GP 17-1-1.The total refinery stock of foam concentrate held in the proportioning truck (or trucks), tank truck and in storage should besufficient to cover the largest single fire demand for 90 minutes, but no less than 1500 gallons. In isolated areas wherereplacement supplies are not readily available through local mutual aid arrangements, a larger supply should be maintained.An additional allowance for training purposes should also be made.Foam stocks should be stored in a sheltered area or building to avoid extremes of temperature and tested as per manufacturerrecommendations. A minimum of 30°F is necessary to maintain reasonable fluidity, and a maximum temperature of 100°Fminimizes deterioration of the foam concentrate. Except for the quantity kept in the fire vehicles, foam concentrate should bestored in its original shipping containers to minimize contact with air, which also causes deterioration and sludging. If theconcentrate is to be stored in large drums to aid in rapidly refilling the trucks, the drum should be covered with a sun shade.

FIRE FIGHTING EQUIPMENT TRUCK➧ An equipment truck is provided to transport the miscellaneous fire fighting equipment which may be needed at the scene of a

fire, including hose, nozzles, fittings, foam playpipes, drums of foam concentrate, emergency lighting, tools, protective clothing,portable extinguishers, etc. Full details are specified in GP 17-1-1.

FIRE EQUIPMENT CABINETS➧ Fire equipment cabinets containing fire hose, nozzles and fittings shall be provided in areas where there is a significant time

delay in obtaining these items from the equipment truck. Normally, marine terminals are the only facilities in this category.Hose cabinets will normaly not be installed in a small, low fire risk plant unless personnel trained in the use of such hose areavilable to respond but an equipment truck may not be justified Details are specified in GP 17-1-1.

FIRE EXTINGUISHERS➧ Portable fire extinguishers shall be provided to enable operating personnel to quickly attack small fires. They should be located

at process areas, berths, loading racks, pump areas, and similar facilities. Travel distance from the protected equipment to anextinguisher should not exceed 50 ft.




DESIGN PROCEDURES (Cont)Extinguishers are located at grade and on major operating platforms such as in compressor houses, on mountings which arewell marked and clear of the ground or platform.Three basic types of extinguishers are used:• Dry chemical extinguishers (potassium bicarbonate powder pressurized with nitrogen) are provided for general refinery

use. They are suitable for flammable vapors and liquids and can be safely used on electrical equipment.• Carbon dioxide extinguishers are recommended for electrical fires but can also be used on small flammable liquid fires.

Carbon dioxide has limited effectiveness in the open, because of wind currents. Therefore, its use is normally restricted toareas such as laboratories and electrical substations.

• Pressurized or carbon dioxide-expelled water extinguishers are primarily used in offices and warehouses where woodand paper fires may occur.

In addition to small extinguishers which can be handled by one person, 125 lb. (57 kg) wheeled dry chemical extinguishersshall be provided at loading racks and high risk process areas (normally one per process unit).Extinguisher details are specified in GP 17-1-1.

FIREHOUSE➧ The firehouse is provided to house the various fire vehicles and central stocks of fire fighting equipment and foam concentrate.

Normally, it also serves as a headquarters for the fire marshal, fire crew and fire communications, and includes equipment-servicing facilities. The building must be heated and/or air conditioned according to the climatic conditions of the location, andprovided with utilities for servicing, i.e., compressed air, electric power and lighting, fresh water, and drainage for washingequipment and hose drying.The firehouse should be located approximately centrally with respect to major fire risk facilities, but in a safe location on a mainrefinery road. A basic spacing of 150 to 200 ft from the process and tankage facilities is required, in accordance with SectionXV-G. Consideration shall be given to the possible impactof vapor cloud explosions on the building, per Section XV-H.A firehouse is considered both and occupied and critical operations building and is subject to the blast protection guidelinesdescribed in Section XV-H.

COMMUNICATIONSA special telephone that can only receive fire calls, equipped with a distinctive bell, should be located at a point that iscontinuously attended. A siren or whistle should be provided, operable from this same location so that the plant fire fightingcrew can be alerted to proceed to the fire with the appropriate fire vehicles. The source of power should be reliable and thesiren or whistle located so as to be audible in all parts of the plant.A means of calling in off-duty auxiliary firefighters is also required. Personal radio or pager systems or contract telephonecall-in services may be employed. Radio or direct telephone communication with outside fire fighting organizations, e.g., localcommunity fire brigades, is necessary to insure rapid assistance in fighting major fires.Two-way radio communication is required in the fire vehicles and in all other refinery vehicles likely to be involved in emergencyoperations, e.g., the shift superintendent's truck, so that overall fire fighting activities can be effectively coordinated andcontrolled.

MARINE TERMINALSSpecialized fire fighting facilities are required for the protection of Marine Terminals. The following features should be included:• Fire Main - Extend the plant fire main to all berths with an appropriate allocation of hydrants, monitors, and hose reels, in

accordance with the layout of the piers and piping, nature of products handled, etc. In some installations, the pier issufficiently distant from the plant facilities that a separate pier firewater system is more economical than an extension ofthe plant fire main grid. In such cases, a single fire pump is provided, taking suction from the adjacent body of water, andlocated at least 200 ft (60 m) from the nearest berth. Backup pumping capacity when required is provided through hoseconnections from fire tugs. If such backup is not available, consideration should be given to sparing of the firewater pump.






• Foam - In order to facilitate the supplying of foam to the piers without incurring the problems of long hose runs andvehicles access, a dry pipe foam system should be provided consisting of piping extending to the manifold area of eachberth and equipped with hydrants at suitable locations for use with hose and portable foam nozzles. At each berth, thepiping should extend up the gantry structure, if available, and include connections for portable foam nozzles and/or hoselines. The shore end of the dry pipe should terminate where foam solution can be supplied from the foam proportioningtruck. Where pier layout is extensive and would require a relatively long dry pipe foam solution system, the time taken tofill the header could cause a significant fire fighting delay and/or the facilities might be relatively costly. In such cases aspecial foam concentrate tank and foam-proportioning system may be desirable, located on the dock at least 200 ft (60 m)from the nearest berth.The design should be based on that for the foam proportioning truck in GP 17-1-1. To enable the foam concentrate tank tobe replenished, either an access roadway for the foam tank truck must be provided, or a filling line from the shore intowhich the foam tank truck can be connected. The foam concentrate tank should have a capacity of 1000 gallons.

➧ • Fireproofing of firewater and foam mains is covered in Section XV-H and Section XXXI-I.➧ • Fire Equipment Cabinet - Provide a fire equipment cabinet at each berth, as described in Section XXXI.

• Fireboats or tugs fitted with boom-mounted elevated foam / water monitors. Offer a high degree of fire protection. Wherethese vessels are readily available, one or more should be equipped with a remotely controlled foam/water monitor nozzlemounted on a hydraulically operated articulated boom. The type of boom, i.e., with or without a platform, should beselected on the basis of local preference.

• Monitors - If tugs or fire boats are not readily available and the vertical distance between the ship's deck and pier make itdifficult to reach the ship's manifold area with normal portable equipment or fixed monitors, then one of the elevated boommonitors referred to above should be provided near the pier manifold. Location should insure maximum coverage withoutundue risk of fire exposure. The foam / water monitor nozzle should be supplied from the dry pipe foam solution andfirewater systems. Selection of boom type, with or without platform, should be based on local preference.

• Ship / Shore Communications - An effective and reliable direct radio communications system between the tankers, firetugs and shore fire fighting personnel is required.

• Access - With the design basis described above, it is possible to design marine terminal fire fighting facilities such thataccess for fire fighting vehicles on the dock structure is not essential. From considerations of fire fighting vehicle accessalone, therefore, the provision of roadways on dock installations is not necessary. On long pier structures [over 1000 ft(300 m)], however, the need to transport fire fighting personnel rapidly to the vicinity of a fire will justify a single vehiclewidth access road. Normal maintenance and transportation requirements must also be considered. If a marine terminal isdesigned without an access roadway, the contents of the fire equipment cabinet at each berth should be increased toinclude appropriate items of miscellaneous equipment, which would normally be carried to a fire by the fire equipmenttruck.

• Breasting Islands - Generally, offshore breasting islands are very compact and have minimumoperator attendance. Afirewater system of 1500 to 2000 gpm (341 to 454 m3/h) capacity is normally installed, consisting of hydrants, fixedmonitors and hose reels, supplied from the shore fire main or by local fire pump. With a fire equipment cabinet and smallstock of foam concentrate, this constitutes sufficient cooling water and foam capacity for a relatively small fire, e.g., at aloading manifold flange. If fireboats were available, they would provide the major fire fighting effort in a larger incident. Ifthe breasting island is critical to the operation of the refinery, additional fire fighting facilities capable of handling a majorfire may be justified. In such cases, the Safety and Risk Section of EETD should be consulted.

• Miscellaneous - Further details and background information are contained in Marine Terminal Fire Protection Review,ER&E Report No. EE.50ER.68, Marine Terminal Fire Protection and Safety Guidelines, Report No. EE.7TT.77, and FireProtection and Safety Guidelines for Marine Terminals, Report No. EE.5TT.81.

COOLING TOWERS➧ Parts of cooling towers constructed of combustible materials are vulnerable to fire where drying out occurs, such as the top

deck above the cooling water distributor or any part of the tower when not in service. Firewater coverage is, therefore, requiredas follows:• In accordance with Table 1 for Monitors.• In addition to the above, cooling towers constructed of combustible materials should be provided with sufficient hose reels

on the fan deck to give total deck area coverage.





FIRE TRAINING AREA➧ A fire training area for refinery fire brigade and operating personnel should be provided, located in accordance with Section

XV-G. The training area should be at least 100 ft by 100 ft (30 m by 30 m), adjacent to a refinery road to permit access bymobile fire equipment, and should have a fire hydrant within 100 ft (30 m). The area should be paved with concrete and slopedto allow drainage of fire and storm water. Design and construction standards shall be the same as used for process facilities.Figure 3 shows the layout of a typical fire training area, with various fire simulations, fuel dispensing systems, etc.

GENERALAdequate sewer capacity is necessary to avoid the additional problem of area flooding (and hence potential for injury andspread of fire) during fire situations when large volumes of firewater are being used, particularly in process areas. Detailedprocedures for sizing industrial sewer systems are included in GP 3-2-1. Consideration also should be given to the drainage offirewater by surface flow in the event of sewer restrictions.While firewater, foam systems, mobile equipment and portable extinguishers as described are likely to continue as the basis ofrefinery fire fighting facilities, new equipment, extinguishing agents and techniques are under constant development. Suchdevelopments should be kept under review and introduced for special applications where justified by economics andeffectiveness.





➧ FIGURE 3 TYPICAL FIRE TRAINING AREA

8 Ft by 8 Ft Steel Plate

1 Inch Perforated PipeFacing Backboard

Standard

1-1/2 Inch Pipe

Flange and Jet

3/8 Inch Opening

Flange With Partial Gasket6 Feet Above Grade

Support

DP15IF03Backboard

Ref

iner

y R

oad

GasolineTank

1000 Gal.

150 psig50 gpm

StorageShed15x15'

Accessway

Hoseand

DispensingNozzle

SurfacedTurnaround

Area

Pump

LPG

1" Pipe

1-1/

2 In

ch P

ipe

Flange

Jet

Backboard

Trench

20'x2'x2'Pan

7'x7'x1'

Pit20'x20'x2'

Surface, Drained Area 100 Ft by 100 Ft

Small SpillsObstacle Spills (Drums, etc.)Large Spills

Spill Area

Prevailing Wind

Valve1 Foot

Above Grade

Standard

1 Inch Pipe

Details of Fire Simulations

Hydrant

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